The ATmega4809 microcontroller communicates with the NINA WiFi module on the Uno WiFi Rev2 via I2C. You are also using I2C for the LCD display. I'm a bit suspicious that the display hardware or the display library code is causing an interference with the communication with the NINA. This is not guaranteed to be the issue, since it is quite possible to share the I2C bus with many devices.
The first thing I would try is to disconnect the display and then run your full sketch. That will tell you whether the display hardware is the culprit.
Next, I would comment out all the code for the LCD in the sketch and try that.
It's also possible that the RFID hardware is the culprit. It doesn't use I2C, so it's not a matter of it interfering with communication on that bus, but it does cover the WiFi module quite well, and thus might be blocking the signal. It also sounds like that thing pumps out a ton of radiation:
Warning: Ensure that personnel do not stand in the radiation beam of the antenna unless they are more than 21cm away from the face of the antenna
so I suppose that could cause interference, sitting only millimeters from the WiFi antenna.
You could try connecting the RFID shield to the Uno WiFi Rev2 with jumper wires, rather than being plugged in to the Uno WiFi Rev2 directly to allow you to move it farther away from the WiFi antenna.
You could also try running your code with the RFID module not connected to the Uno WiFi Rev2, but with the LCD attached (so that you're only testing one variable at a time). You would need to modify your code so that it will still run, even after the initialization of the RFID hardware fails.
The ATmega4809 microcontroller communicates with the NINA WiFi module on the Uno WiFi Rev2 via I2C.
a small correction: Nina firmware doesn't use I2C. crypo chip is on I2C.