Today I had a strange issue with my Oneplus 7 pro GM1913 running OOS 9.5.5, device unlocked, twrp and rooted. My device ran out of charge and was turned off. When I plugged into the charger, it boots up and for a few second the oneplus logo and charge the device for some time page came in and then the bootloader unlocked screen came in. I haven't charged the device offline after the battery ran out, it was my first time and i thought it was supposed to be like that. But after some time also it was on the same page. Then i plugged out the device and it was stuck on that page. I tired hard reboot, tried to connect to computer. Nothing was successful. Computer showed unknown device and failed to successfully connect. Not recognised as adb device shown nor fastboot device. Then atleast I tried entering into fastboot mode by pressing power button + volume up. At that time it rebooted into system and then everything was okay. But then i noticed i also lost the twrp recovery. Then i had to flash twrp through magisk manager.
Anyone has any idea what happened? Thanks in advance