I experienced similar behavior. Yesterday I felt it could be caused by an Adventure Lab Cache we did in between as these automatically added to the number of founds, but today I again experience the number jump quickly, as if there is a loop in the count.
I do not save drafts in the Cachly app, but send direct to GC.com where they are saved as draft at GC.com.
The first find is counted properly (# of finds on GC + 1), but the second and further ones add “ghost” finds?
iPhone Xr
iOS 14.4
Cachly 6.1.11 (3)