Hey Aldo:
So CE refers to "Continuing Education" - it is a distinction that contrasts the Good For Life (GFL) variant of CompTIA's certifications that ran out in 2011. Used to be that once certified, always certified. But CompTIA altered the rules to create an "expiring" certification and a program that allows folks to maintain their certifications through continuing education.
If you are using the CE program to maintain your certification, you do have to keep up with the CE fees. The way I understand it is the expiration date keeps moving downstream as you meet CEU requirements and pay the fees. Once you stop, the three year clock begins again. (if someone can correct me on this, please do, if I'm wrong)
I've personally never used the CEU program - I opt to test/retest every few years to keep current. The optimal plan is to take the CASP every few years which will refresh everything that has a CE designation (like Cloud+, as well as the Trifecta certs).
/r