Galaxy S21 FE 5G - No cable charging

There are a few instances where software can cause charging issues, so I would make sure that the device and all apps are fully up to date. You can also try to do a hard restart by holding down the side button and the volume down key for about 45 seconds until it restarts. This restart is the replacement for not being able to take batteries out. Finally, I recommend you wipe the cache partition. This support page has the steps on how to do that. As long as you only wipe the cache partition, you will not lose any of the valuable data on the device and will just be clearing out some of the digital junk that can cause various issues on the phone. 

If you still have issues charging her phone after doing those steps, I would reach out to talk about warranty options. I think in your original post you say that Samsung holds the warranty on it, so best bet would be to contact them. You could check your T-Mobile account to see if there is a warranty through us still. The manufacturer warranty is good for one year from the date of purchase or you may have an extended warranty benefit if you have Device Protection or Protection 360. One thing to keep in mind with any warranty program is that physical damage line cracks on the screen or casing and water damage can void the warranty. Hopefully that is not the case for your wife’s phone. 

Have a great day!