This worked for me to be honest, this issuewas bugging me for a week then I remembered seeing something that suggested clearing cache after updating even if you don't notice any bugs cause it's generally good for your phone so thought why not give it a go, battery charging was really slow but now it's back to normal, battery discharging was soooo quick, it still drains more than android 9 but it's alot better than before, so yeah clearing cache seems to work!
