Last night I tried to turn my Samsung Galaxy S9 on, but instead of turning on like usual, it would just stay on the AT&T screen. After maybe over 10 minutes the phone would shut off and then turn itself back on and the cycle would continue. I wasted a couple hours of my night, browsing the web and wiping the cache partition. Those didn't work, but then randomly on one attempt my phone turned on, and everything was working. My phone was at low battery and died soon after, and in the morning the issue had started happening again when I tried to turn my phone on.
I am able to use the volume up + Bixby key + power key to boot into recovery mode. Some important things I can do is updating from ADB or an SD card, and I can reboot to boot-loader.
Before this happened I had gotten a bit of water on my phone and the speakers made a terrible garbling noise whenever sound was played.
What can I do to solve this? I would also like to backup my data, before proceeding with anything if possible.