Hello, We have an outdated server in 7.0.5 . Some users have folders with Pending state . It's due to the size is suddenly update with -1 and with correct size a few moment later . Do you known some issue with 7.0.5 ?
FYI : The upgrade in OC10 is very close.
7.0.5 has too many issues to even start with looking into such problems. Forget about this outdated version and move on, you don't want to waste your time with this old version.
I just want a feedback on this version . Do you confirm me that they have troubles with oc_filecache in this version?
7.0.5 was released 2 years ago. I highly doubt that anyone in here can confirm or remember if such issues existed back then... 
Besides that, 7.0.5 contains so many bugs and public known security vulnerabilities that you really shouldn't run something like this on a productive environment.
In the release list, you can see some of the changes between versions:
https://owncloud.org/changelog/
But these are only some of the changes, you could try and hunt down fixed issues on https://github.com/owncloud/core/issues
There are chances that you problem was fixed. In order to get it fixed, you have to reproduce it with a still supported version. Make a backup of your system, be careful especially when you use the encryption app.