In the "No Command" screen, hold and tap Volume Up once to enter the recovery menu. Select Wipe data/factory reset .
The firmware you flashed overwrote the NVRAM partition (which holds radio calibration data). Solution: This is serious. You need a backup of your original NVRAM, or you must use a tool like Maui META (for MediaTek) to rewrite your IMEI. Always back up your NVRAM before flashing custom or different region firmware. celero 5g firmware
Sometimes connectivity drops (like 5G falling back to 4G) can be mistaken for firmware bugs when they are actually related to the In the "No Command" screen, hold and tap