@Olegr 

I've have an iPhone 12 Pro Max using iOS 14.4. No problems on my Archer A20, it sees all 3 SSID's.

Possible reason could be:

• Channel frequency needs to be changed (however that shouldn't matter?).
• Security needs to be changed.
• Private Address might need to be turned off (doesn't explain the TV though?).

I assume these all worked with the OLD router? If so, are you using the same SSID's? If so, on the devices, FORGET/DELETE the old network connections. Might be looking for the wrong IP Address of the router.

If you enable the Guest 5Ghz, do they see it?

@Olegr 

I would try changing the 5G channels to any of the available values.

@IrvSp 

SSID are name and name_5g, not same name.

The problem is that with android phone / Laptop all is OK, only the iphone12/TV makes the issue.

@Olegr 

I would recommend reaching out to Apple support to see why that may be the case since you are able to verify the router 5G is broadcasting.