I've been having this issue and I know 3 others with the same. I've tried cleaning the port, dying to port, restarting, deleting recent apps, cleaning the cache, deleting the USB settings data... basically everything short of factors reset (which is completely out of the question). The phone never got wet, the notification alert just showed up one day. I cannot fix the UNPLUG CHARGER alert on my phone. I cannot cable charge and this has gotten to my break point. I luckily have plenty of wireless chargers but this is ridiculous.
3 cables and an external battery pack. I have friends with the same issue and we have all tried the same thing. This is like some wild conspiracy at this point 🤣
I will say I have Both Galaxy Note 10+ and the Galaxy Note20 Ultra and Samsung tec support have always been able to Rescue my Devices. Even when I loaded a 7.0 systems launcher reader
Go to Samsung Tec support and have them Rescue your Device they will Text you a Code giving them permission to see what's happening with your phone. This happened to me was thru Samsung Rescue. And I had to remotely turn my Device over to them. And they were fist. Like 5 minutes