Thanks for your quick reply. Sorry for my late reply. I have spent the last 4 hours testing a lot of different stuff. All described below.
In short:
Anything that has to do with a Envato template does not work.
The only thing that works is creating a new page with Elementor when it is the only plugin enabled.
I will continue testing and let you know what else I find out. Hopefully you can help me further with the following, (very) in-depth information. Thanks in advance
I am writing this as I go so I won’t forget to mention anything.
I upgraded the memory to 256 and made another new page. I did the same thing as I did before, added a section with some text and an image, added another section for the carousel (found under general ‘Image Carousel’) and just kept going until everything would get deleted, but… that never seemed to happen. Eventually I got to the point where I was just adding random options because I didn’t know what to add anymore and it never deleted itself.
I tried everything to break it again, but after an hour it still works. So I decided to install Envato and essential addons for Elementor again and start working on the template that I wanted to use. After about 10 minutes everything was deleted again.
I looked into the envato settings and saw that my upload size limit was set at 2mb, I increased it to 100mb. Downloaded the template again and started over. Yet everything still got removed after a few minutes.
At this point the test page without a template still works, so I am getting the feeling it is a envato problem. To be sure I deactivate envato and make another test page using functions of Essentials Addons for Elementor. If this page also survives longer than usual then I know it is Envato who is screwing up.
After creating the new empty page, with no template, I started adding a section, with text and an image, went over to another section with a title and carousel. Everything OK so far, added another section with a title and text but after updating everything was removed again. So I suppose it might not be because of Envato, maybe it is Essential Addons for Elementor (even though I have not used any of their functions yet).
So now I will deactivate Essential Addons and activate Envato again. Create a new page, add a Envato template and start editing. After editing for a couple of minutes everything was once again removed. I guess both Envato and Essential Addons are causing the problem?
So I will deactivate both of them and make another page without a template to test. On this page everything got deleted aswell.
Next I will try to delete a plugin (essential addons), maybe it still interferes with the website even when being deactivated. I create another empty page, add some random stuff and this also seemed to continue to work. At this point I think that it only works when element or is the only active plugin and no other plugins are active for elementor. But I really want to use a template from Envato, so I willa activate it again, make a new page with a template and see what happens. On the last page I created I think it removed everything very, very quickly, but I’m not sure so I kind of started over again. Maybe this is the trick to a working page, starting over after getting reset.
So I created another page, added a Envato template and started editing. Eventually everything got removed again, I started over in the same page which worked for some reason (usually updating the page after everything getting removed does not work) but that also got removed again.
At this point I have 2 pages made with elementor without a template that are still alive.
So I guess Envato has to be deactivated to work, which is okay because the template I want to use is saved in the templates folder. Now I will try to deactivate the plugin and use the saved template instead of implementing the template using the envato plugin in the page.
So I create another page and try what I mentioned above. Also this did not work.
Now I removed Envato completely and saw that the homepage template was still saved in my templates folder. I decided to edit the template directly, instead of putting it on a page and then start to edit this. Also this did not work.
Anything that has to do with a Envato template does not work.
The only thing that works is creating a new page with Elementor as the only plugin enabled.
Also, I installed Malcare to run a (free) malware scan on the site, it did not indicate any corrupted files or malware. There are probably better scanners out there but none that are free as far as I could find. Thought it was worth a shot.