Keeps loosing wifi connection

I have a couple of unifi 6(lite/+) access points.
I’ve set up a specific IOT network on 2.4 GHz, which all my iot devices connect to.
Over the last 24 hours, it has lost wifi connection 12 times.
It is so bad, that I’ve gotten emails frequently about the sensor being lost for 24h, and I’ve had to set up a special flow that recycles the power if it can’t be pinged locally.
It’s a NodeMCU in the box. The box is placed outside a window, and there’s an AP behind the window 5 m away, so the Wifi is ok.
The sensor shows:
|WiFi|Signal|-60 dBm|
|WiFi|Kvalitet|80 %|

I don’t see these frequent disconnects with other ESP based systems. I have a lot of wifi switces etc. and they don’t disconnect all the time.

The sensors connected to the NodeMCU are a SDS011 and a BMP280
The PSU is a 5V/2A.

Is the firmware that bad that it will loose wifi that frequently, or what is going on?

It happens sometimes and I have never found out why. Change the PSU anyway. Is there a WPS option on your router ? Is there a guest network ? The 2.4 and 5 networks are really splitted with diefferent names ?
I had a sensor 15 meters far from the router through 3 thick walls before and no disconnections.

Yes, the IOT network is a seperate VLAN and WLAN (called xxxIOT), it is 2.4 GHz only.
No WPS on the router (it’s a unifi system).
Yes, there is a seperate guest WLAN, not connected to the IOT WLAN.
I did replace the PSU as the old one didn’t give enough power to keep the display showing proper stuff, but the replacement didn’t change anything.

Can you get the serial logs to see what exactly happens ?