Also in the UK and I got the ASC8 update yesterday. Didn't clear the cache until just now, but I've now noticed that the phone feels snappy, the fingerprint sensor is MUCH faster (light touch and opens very quickly), and reverse wireless charging is much better and more intuitive. Before clearing the cache the battery life was pretty much the same, but now that I've cleared it, I will check back in a few days to say if it has helped at all. Fingers crossed!
Power the phone off, and then once it's off, hold down the power + volume up + bixby button until the android man logo comes up.
Then it'll come up with this retro looking screen, and you use the volume up and down buttons to navigate to "clear partition cache". Once you're on it, click the power button to select it. Then just reboot the phone, and it should restart as normal. Give it a minute or so upon restart and hopefully you'll start seeing changes! I noticed the faster fingerprint scanner immediately! Very happy, cause mine was pretty slow...
An updat to my S10e.
Early last week my phone had the same battery drain where Android System had high battery usage.
I performed a Partition Cache Reset and cleared Data and Cache from the Google Play Services. This seems to have helped but not fully resolved the issue.
3 days ago my phone received a firmware update, I installed this and perfomed the following:
After this the battery drain has been fixed, last night (midnight)I took the phone off the charger after it charged to 100% before I went to bed, at 5am this morning (5 hours ) it was at 98% on standby. 2 % consumption on standby for 5 hours is excellent.
oh I did uninstall and reinstalled Whatsapp as this did have high batter drain, this seems to have fixed this app battery drain.