Hi @vini13
Try using the tablet's WiFi as close as possible to the network router in your premises i.e. <10cm and check if it works OK and that it maintains a stable connection.
If it works OK it may be a loose WiFi antenna connection that is the problem, (supplier example only to show what the antenna looks like)
Here's a teardown video for the tablet that may help.
The antenna can be seen being removed from the tablet at ~1:51 minutes into the video.
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