Ok, look what I did (So far solved). I was reading looking for some solution and I found this:
https://support.apple.com/en-us/HT201262
There is a part that says: “It also does a basic check of your startup disk, similar to using First Aid in Disk Utility. And it deletes some system caches, including font caches and the kernel cache, which are automatically created again as needed. "
So I gave it a try and after restart the problem was solved.
However I reinstalled the cleanmymac just to test if it was the problem, but the problem with the quicklook did not reappear.
I'm NOT a fan of cleanmymac, understanding what you say I'm not going to use it again, but since I have an MBA, my main disk is low on space, so I ask you if there is a disk monitor or something similar, or do you recommend don't install anything additional and manually view it in “About this Mac”?
By the way, excuse my English, I do the best I can.