After installing TWRP Recovery my phone only reboots to Fastboot

I was trying to boot my phone, and after installing TWRP I ended up with the destroyed image error. I fixed that by reflashing to OxygenOS EU. I’ve followed your instructions to install TWRP again - I wasn’t installing to recovery A and B - but the phone will only boot into Fastboot and TWP won’t load.

Any ideas?