Redmi A3 constantly turning on screen with notification

"Network has no internet access"

"Private DNS server cannot be accessed"

I use NetGuard to block Wi-Fi access for most apps – including system – and I often turn Wi-Fi off completely.

Whenever the screen turns off, my Redmi repeatedly shows a connectivity notification about having no Internet access or being unable to reach the Private DNS server. The notification wakes the screen each time, causing unnecessary battery drain. I use nestdns as my private dns too.

How can I stop this notification from being generated and waking the screen?