How to get into twrp / reinstall neccessary?

[andPS2]

Hello,
i have a question about getting into Recovery or maybe i have to install it again?
So i installed twrp following this guide

Install LineageOS on walleye | LineageOS Wiki

wiki.lineageos.org

At first i installed the Lineage OS recovery but wasnt able to flash a ROM with that so i switched and installed twrp.
It was installed to slot A.
I then went ahead and installed an ASOP ROM.
Now the ROM is working fine and i wanted to go into TWRP and do a Backup.
However i cant get into TWRP. Not with key combos nor with adb reboot recovery.
All i get is the fallen Android Robot picture.
I guess i wrote the image to Slot A as well and now have no recovery left.
Do i have to flash TWRP again and this time to Slot B?
I dont wanna brick anything by accident as i have seen some posts where people switched Slots and got bricks / semi bricks.
Thanks for any help or clarification.
Kind Regards

 

[Deleted member 11324681]

Hello mate, i never reinstalled twrp on my pixel 2 after catching a bootloop after installing it and then flashing magisk so stuck with using fastboot to fastboot boot twrp when I wanted to flash a ROM/mod.
Sounds strange that twrp was only on 1 slot as the twrp installer zip should flash both slots when flashed?
With regard to losing twrp you'll probably find that the new ROMs recovery has overwritten your twrp recovery during the flashing process giving you a stock recovery again (Fallen android). When I was using a 6T which is an A/B slot device you always had to reflash the twrp installer after a ROM flash to keep twrp installed.
I'd check the official twrp thread re backing up with twrp as it did have problems either backing up or restoring last I used it.
Hope that's some help.