@Mattia2 If your TL-WA850RE(EU) is HW Ver:1.20 the it supports only RE mode (HW version is printed on the RE sticker):

@Suzie_Wardy Here's a video guide on how to setup a router in AP mode. To manage your TP-Link routers you'll need the tether app. Deco app is for managing the Deco systems. These are the routers...

@Owatrob That seems like a faulty power button switch. You may contact your local tech support for assistace on this.

@guyd2 According to router HW version, make sure that you're with the latest FW release for your device. You can set a static wireless channel for 2.4 GHz band (i.e. 1, 6 or 11) to check if there's...

@Raamim GX90 supports OneMesh for now, but it's planned to support EasyMesh - details. When that happens you'll be able to create a mesh network between two of those.

@Brickadoon Ther's a compatibility list for 4G dongles that VR400 can use, just select your country - here.