Install nicelock (or finelock) from play store, open the app and click on 3 dots in top right corner and open xda support thread, here you'll see Downloader companion website, click and all good lock modules will be shown. Now click on any module, yo...
Strange. I'm using s20 fe and it's much smoother now on oneui 4. No lags or bugs at all. Same is the case with most of the s20 plus users as i know. Wiping cache may reduce the problem and reset if possible as a last option.