@SpaceWalker73 have you tried this update that adresses the dhcp issues on 1.5.1 specifically? https://community.tp-link.com/en/home/forum/topic/674472 

@David-TP is it normal that 1.5.1 is still official available as download where as it gives lots of people severe issues (like DHCP not working)?

  @David-TP I tried to use ap mode and didn't work.

im from Brazil. My model is Deco X50(US) Ver 1.0.

i used the app yesterday. It showed update available. I updated using the app and now the internet is not working.

ping 8.8.8.8 works but there is no data transfer. Can't access web sites, streaming, etc Speedtest.net shows error.

downgrade is a complicated procedure. We need official firmware fixing the issue, to update via app.

I opened a ticket in tplink brazil as well.

I think I found out the problem here.

the QoS was enabled with 0.1 rates.

I never set that -- at least I don't remember doing it. Could it be a side effect of the firmware update?

I disabled QoS and now it is working.

Hi  @David-TP, any feedback on above? 

Thanks! 

  @JanRekenaar I missed this post initially so thanks for pointing it out - after updating to the BETA version of the 1.5.1 v1 firmware the issue about devices showing offline has vanished, at least for 2 days now. Earlier to that with the original 1.5.1 firmware devices where showing offline no longer than 24 hours after a X50 reboot
Thanks!