Hi,
I think this is a Samsung/One UI issue rather than A14 issue. There are many posts about this issue from s8 upto s22ultra. There are some suggested fixes which didnt work for me but I found a solution.
So a work around first is to remove your sim card, this should stop the reboot loop. Some said to turn off wifi would also fix issue but not for me, and as soon as it turned back on wifi was reenabled and same with bootloop.
Get your wifi password written down or somewhere easy for soon.
Next you should make a back up. Samsung and google both have an option in the setting, but maybe the switch option is best (even set up an spare android phone to make sure everything works before deleting), can install on any device and then transfer using wifi or cord (I used samsung and some apps dont appear to be there but maybe I didnt wait long enough for the backup but Im pretty sure it said it had finished).
Now you have your backup you can get into the something mode, many people say hold home power and volume down, but that gets the download screen, if you press power, bixby (I used bixby button but maybe not needed) and volume up, hold them all in while the device screen boots, then as that dissapears and the samsung one appears release the power button and bixby while keeping the volume up button pressed. (Sometimes in the bootloop the first screen didnt appear and the samsung one was the only one, then it didnt work, just keep trying as it turns off and probably a blue light in top right of phone) After a couple of seconds a blue screen comes up and tries something then does an error no command and after a few seconds it goes to a black screen with options. Use the volume up and down to choose and then power button to select your choice.
Not sure which is required but what i did was delete partition (as advised in other threads which didnt do musch but had to redo wifi password). Then I tried a graphics test and it started deleting something, then back to the black screen, then I tried the locale test and I actually had about 150 choices of languages and locations, SO i chose en_AU which was number 25, and then back to black screen. Then I chose the last option (the factory reset wasnt working previously to this). The last optionnot enough space for boot.. something and it looked like it did a factory reset but gave some warning. Then i got a new software update warning from this year 2024 rather than 2019 or 2021 so I downloaded and installed and problem was fixed. I did another factory reset and it did everything fine this time as couldnt do it through setting previously.
Everything working perfect now, plus a new UI. Probably a corrupted file but could be in different parts so different people have different but similar fixes. I noticed the IMEU number was missing from the about settings previous but now there are two for the two sims. (I used a code previous to see the IMEU number but was nowhere in the about section)
Anyway hope this helps somebody as it took me hours following guides and what not but then just played around and worked it out. Did NOT need odin or flashing, just phone and internet connection plus a second device to backup as precaution.
Good luck
