Ist TP-Link Deco gut?

With WLAN systems, Position of devices to be reasonably planned. Simply put things somewhere (in the radio shadow behind metallic obstacles, radiators, grids, aluminum foil, sheet metal doors, sheet metal shelves, PC case!!! is not a good position), can cause unfavorable situations.

Even too many devices can be disadvantageous.

• The motto is “only so much accesspoint as necessary“
• and not “so many accesspoints as possible“.

For too many access points in confined space is bad for performance.

Also the distance between access point and internet access (~main Wi-Fi router) must not be too large. A wall in between is ok, several walls in between, can cause interruptions of the WLAN connections (as described by you).

And if possible / feasible, connect the access point to LAN cable, because the wireless radio links to the Haup Wi-Fi router can be unreliable. Each LAN cable connection instead of a wireless radio connection, relieves the WLAN radio system, and more “radio performance” remains for the unavoidable wireless radio connection.

Wi-Fi must be tried by good choice of positioning, and then test and measure whether it is good/sufficient. If not, then improve the critical “radio corners” (other position, shorter distances).

With the free Android app Fritz App WLAN, you can actually test the WLAN illumination well, and discover WLAN radio holes.

https://avm.de/products/apps/fritzapp-wlan/

Good luck!