I am using https://github.com/39aldo39/Flym-DecSync. It is not updated recently. But it is the best I got from Fdroid after trying almost all.
I am using filen for cloud. It has E2EE and gives 20 GB if you use below link. I think it is a good deal. https://filen.io/r/d5a92a596e8518e27b0db303e73e8107
I am using https://github.com/39aldo39/Flym-DecSync. It is not updated recently. But it is the best I got from Fdroid after trying almost all.