@TP-Link_Deco I contacted the local TP Link support in my country, and he could not help. The power adapters for the Deco P7 are not available from anyone locally and I find it a bit strange that there is no such thing as a replacement, since this product no matter if it is discontinued or not should not become trash because of a power supply failure or a broken power supply cable (as in my case, the powersupply I own that does not power my Deco P7 is perfectly fine, it is only the power cable USB-C connector that is broken).

Okay for all you folks out there who cannot find any replacement power supply, here is how you can fix the Deco P7, but you will lose the Powerlinke backhaul on that unit you use my solution:

Buy a USB Wall Charger that supports USB-C Power Delivery (PD) 12V/1.5A and a USB-C to USB-C cable. This solution I have tried with my P7 Deco and it works file. The P7 Deco that does not have a powerline backhaul I would then place in the middle so that the most farest away Deco units will get the powerline backhaul feature, e.g. Deco P7 with provided adapter on top floor, 2nd one with the USB-C PD wall charger, middle floor and the last Deco P7 you put on the ground floor plugged also in with the original Deco P7 adapter. You then will get the backhaul running from top to ground floor (green LED on power adapter = powerline backhaul is working). It does not matter so much if the Deco P7 does not have the powerline backhaul, since it can connect to the other 2 Deco P7 using the 2 WiFi bands.

If you only have a 2 Deco P7 kit, you will lose the powerline backhaul with my solution but you will still be able to continue to use the Deco P7 units. And please rember any Deco unit can join your mesh, so you can also combine with any other from that range as long as you pick at least a AC1200 model, your WiFi coverage will not be impacted.