this is the type of problem which is difficult to solve here, because it require to have a look to all theme files (and the backend in certain occasion) and cleanup the mess left by uninstalled apps.
Anyway if you like to try to dig into the code by yourself the best way is to find a clean version of the theme (maybe the previous version you published) and download both that version and the live one on your computer and try to compare the differences using a dedicated software (e.g. WinMerge, BeyondCompare) and clean the live theme.
If my answer was helpful click Like to say thanks
If the problem is solved remember to click Accept Solution