So if you provide a hotspot inside the same room, it still cant find the access point?
You can try resetting the network configuration on your TV, although I doubt it will help.
There have been numerous posts in this forum regarding connectivity issues (I suffer from a similar form of a problem with my QLED. The access point is 20 cm behind the TV, direct line of sight).
You could check my post and confirm if its the same behavior: https://eu.community.samsung.com/t5/TV-Audio-Video/QLED-2018-models-real-world-experience-firmware-v...