USB access restriction

I have an iPhone 8, I've noticed since IOS13.1 and now 13.1.1 sometimes when I plug in my charger it gives me the USB device restriction, It instructs me to unlock the phone which I do but nothing happens. I unplug and replug my charger but nothing. To get my charger to work I have to turn my phone off and back on again and it will work just fine. This has happened twice to me. I'm thinking this may be a bug since it's an intermittent problem but not for sure. Anyone else having this issue? I guess as a work around I could try turning off USB restriction in the mean time.
Thanks