Rohan simply restarted the phone once after 24 hours, and everything smoothed out.
If you have a running Android 10 (Go edition), and you see the official Android 11 update in Settings → System → System Update : tecno spark 6 go android 11 update top download
No, an OTA update preserves data. Manual flashing via SP Flash Tool will wipe everything. Rohan simply restarted the phone once after 24