Unbelievable that tp-link do not solve the issue. Only explanation is that it is hardware issue. I've tried everything. Moving "a little bit" the P9 or change plug or cable are not acceptable...

@S13 Same issue here. I use Deco P9 in access point mode. When issue happens it's always the same, there is no more connection between main Deco and the modem. The modem show connected IP for the two...