The Riddle wrote

do you have an opinion or a solution?
do you really think that an AC50 would solve the problem?

Probably support meant to use omnidirectional outdoor APs with AC50 (the CAP300-Outdoor comes to my mind) to supply an area with WiFi. You could also use an EAP110-Outdoor if a standard AP mode is sufficient. As for the PtP link CPE510/520 or CPE610 would be best on large distances (> 150m).

I'm not sure what your exact network topology is (maybe you can draw a picture) with 5x TL-WA7210, but you should keep in mind that this device is designed for directional links; it has a directional antenna built in. While it could be used also to feed standard client devices as a classic AP, this isn't true the other way around: standard devices have no directional antennas and can't connect to a 7210 over long distances.

That's why support did recommend a CAP300/AC50. Also note that AC50 can not be used to control a TL-WA7210. Draw a picture of what you want achieve to make clear what you are trying (include distances please).

Ok, I got it. You want to set up a WISP scenario.

To do so, I would use client mode rather than bridge mode for the WA7210 in building C. Bridge mode will make all sorts of trouble such as bad coverage of the area outside the antenna's beam width (60°/30° H/V) and especially open doors wide to the hidden node problem over such a distance. If you connect an indoor AP to the outdoor WA7210 in building C anyway, there is no need to use it in bridge mode.

Devices in building B could probably connect to one of the APs in building A, but devices in building D and E most certainly won't be able to do so. Their omnidirectional "antennas" (often just a piece of metal such as the metal frame on an iPhone) are just to weak to provide a stable link to a TL-WA7210 over such a distance (the WA7210 could be seen for the SOHO devices, but the SOHO devices are not strong enough to send something back to the WA7210).

Always use a pair of directional outdoor APs in AP <--> client modes and connect another indoor AP to the WA7210. Make sure the local indoor APs use other channels with enough distance (5 channels) from those used in outdoor APs for the directional link.

If you ask me, I would have installed a WBS510 in AP mode with TL-ANT5819MS (120° beam width) at building A and four CPE510s at each other building (all in clear LoS to the main AP). For the local WLAN I would distribute it locally using a cheap SOHO indoor AP connected to the CPE510 by wire.

Of course you could do that with TL-WA7210, too: just place one at buildings B, C, D and E and use a WBS210 with TL-ANT2415MS (alternatively two or three TL-WA7210) as the central AP(s) at building A.

The Riddle wrote

Tried in client mode..Signal from AP2 is absurdly lower than in bridge( at BRIDGE survey)On my iPhone I get 2 Sec of connection and the “no internet connection”So nothing changed ...
Actually i’m In C building

In client mode AP2 has no local WiFi signal! It's a client and - compared to bridge mode - it does not offer a local AP.

Thus, your iPhone is connecting with the main AP, not with AP2, and as I said, iPhones are not capable of working over such a distance. You will see the SSID of the AP, yes, you probably can connect to it, too, but there will be by no way a stable data link, because WiFi quality of iPhones do not compare with those of a directional TL-WA7210. So, your experience is absolutely normal and what can be expected from such a setup.

Again: use the AP1 <--> AP2 link only for supplying the buildings with an Internet access (kind of a transfer network, not for other clients!), but use separate local APs connected to the directional link via patch cable for distribution of the WLAN to local iPhones, laptops etc. inside the building.

The Riddle wrote

you refer to AP2 as the main antenna on building A (dedicated p2p for building C)?
AP2 is set as standard AP and had no disconnection issues in the last 4 days

Sorry, my fault. I meant the second AP in building C. Also "AP" is a bad term since if it is being used in client mode, it is no AP anymore. "Station C" would be a better term (this is also the WiFi mode if working as a client: STA mode).

yesterday as you suggested me i changed the operation mode from bridge to client, got 2 sec of internet connection and then "no internet connection" again.

Let aside Internet for a moment. Check step by step what is working and what is not working and why.

Use static IP addresses for all devices during the test, do not use DHCP (even later on use static IPs for stationary devices, but double check that there are no IP conflicts).

Wirelessly connect station C to AP2.
Check wether you can ping AP2 from station C with its built-in ping.
Check wether you can ping the main router from station C, again with built-in ping.
Check wether a laptop connected to the station C can reach station C, AP2 and the main router.
Check wether the DHCP from the main router assigns an IP to your laptop (set it to DHCP to test) still connected to the LAN port of station C.
Then check wether an indoor APX (not a wireless router!) connected to the LAN port of station C can ping all of the above.
Then check wether your laptop connected wirelessly to the indoor APX can ping the main router, again with a static IP and also using DHCP.

Then - and only then - check wether you can ping an Internet site (e.g. Google DNS at IP 8.8.8.8) over the whole link.
Next, check wether DNS is working as expected. If it does, you can load web sites.
If any of the previous ping test fails, you don't need to test for web/Internet access, it's broken at some point.

It makes no sense to test Internet access before having checked the whole chain laptop ))))(((( indoorAPX <----> stationC ))))(((( AP2 <----> main router as described above.