@FeliA Here is the article I used to downgrade the firmware. I hope this helps you as well... https://www.tp-link.com/us/support/faq/2958/
Forums/ Bug Report
Prior to updating my network from 1.4.9 to v1.5.1, my network was running flawlessly. After updating my 3 Deco5v3 units to v1.5.1 firmware from v1.4.9, my network became completely unstable and was...
@Ikkie I spent 3 days trying to get my 3 Deco M5 (V3) units working correctly with the 1.5.1 / 201022 build firmware. I was never able to - which is really bad with me and my wife working from home!...
@AnotherMJB From what I have observed, running the Network Optimization can come back and say that a channel is congested. Allowing the optimizer to Fix the issue results in it selecting a new...