So when i went to root explorer today exploring data folder inside persist folder i noticed something strange, even after restoring my original non broken persist.img these files did not change as per my thinking and have newer calibration dates than that of 2019.
so what i did i copied data and engineer mode folder from my original unbroken persist.img after extracting it, to the Persist folder inside Root/mnt/vedor and merged both folders. this brought me back having all dates to 2019 except gf_persist.so and autoCalibrationParams.so.
then wat i did i rebooted and used command dd (dd if=/sdcard/persist.img of=/dev/block/bootdevice/by-name/persist) to copy back my original unbroken persist.img.
rebooted and Boom now i have finger print working just like new. didnt even needed to use any fix or anything.
and now my question is... why even after flashing and dd'ing my persist.img many times the persist folder files were not getting modified? doesnt this partition flashing is actually re writing these files inside Root/mnt/vendor/persist ???
so many questions but no satisfying answer but im really very happy with your support and all the healthy inputs ) double thumbs up to the efforts you guys are putting in this forum.
As you probably found out by now, the FP scanner stopped working like new. It seems to only work like new after first following the steps posted. After a reboot or two, autoCalibrationParams.so gets updated (as it should) but it makes the FP scanner only work a small percentage of the time/works like crap. I've pretty much given up trying to fully understand why it does this and there is no permanent fix (besides sending it to 1+ for a fingerprint recalibration or motherboard replacement)