First of all, website don’t change by itself.
Your UpdraftPlus plugin is capable of back up and restore.
I have never used this plugin, but you can check if it has an automatic restore setting, disable it.
Disable and remove any plugin that you suspect is causing you issue.
You mention that you are unable to let changes update on your front end.
If you have a cache plugin such as W3 Total Cache or WP Super Cache, you will need to purge the cache content, then clear your browser history in order to allow latest content to update on your front end.
If you are still unable to find what’s causing this issue, you can disable one plugin at a time, to find out which plugin is causing this issue.