Fastboot mode is essentially a display-only mode on this device. If you need to flash firmware, unbrick, or install TWRP, you must use SP Flash Tool and Download Mode (Volume Up + Insert USB cable).
This is normal. To truly fastboot flash anything, you may need an unofficial unlock tool or an older firmware version that had a vulnerability. how to open fastboot mode on oppo a37 better
: Go to Settings > Additional Settings > Developer Options and turn on USB Debugging . Fastboot mode is essentially a display-only mode on
: Go to Settings > About Phone and tap Build Number seven times. Enable USB Debugging or install TWRP
If you entered this mode by accident or are finished with your task: