Did you patch the boot.img of your phone using magisk?, sometimes of the boot.img is not latched by magisk when you try to reboot normally and then again go to recovery mode the flashed recovery goes back to stock recoveru. I faced sucg like error on my phone I fixed it by patching the boot.img via magisk.
(23-03-2019, 04:25 PM)nokolbuzz Sir, it contains recovery.bin ... please see the screenshot.
1. Hope you're booting straight to recovery mode after flashing and not booting up the phone first
2. Hope you made a full backup because we might also consider the bootloader approach
3. What message did the tool give you about DM Verity, found or not found?