FWA510 loses 5G connection several times per day / Loud noise etc etc

My FWA510 loses 5G connection for around 20 seconds several times per day. I have gone though all troubleshooting advices from this forum and Zyxel page many, many, many times, so please no need to link them anymore here as a solution if there's nothing new to add.

Additionally router is very loud, as some fan starts running inside after couple of hours of use. Noise is so loud, that it would be impossible to sleep in the same room, or even work beside. My originally purchased FWE510 was replaced due to noise, but here we go again. Router is placed on table with lot of space around with room temperature max 20 degrees.

Seems that there's really thoroughly wrong with the firmware and design which is really shame, as I thought I bought high end product to have as stable and reliable internet connection. At the same property ZTE mobile 5G router with same 5G subscription works everywhere fast and without any disruptions. According to ISP my location is very strong area from them, and they were surprised with the issues.

I have tried to cancel the deal with the seller, but they insist to contact Zyxel support. As far I'm concerned there's no solution for constantly failing 5G connection, and ridiculously loud fan noise is just one of features that hasn't been advertised.

Maybe you could at least assist in getting refund by explaining there's no solution for the issues? If not, guess it won't do any harm to paint this box of misery orange so I can have 400 euro traffic cone at least.