while this posts mentions shades, I believe this is a QS issue...
I have a client with a large QS system with a mix of RF devices (shades, keypads, dimmers/switches) and RPM controlled lighting. System was rock-solid and client wanted a tweak in the programming; made the change, uploaded (not a "force full upload"), checked the new programming to make sure it worked and left.
A few days later, client calls and says his RF controlled shades are not working properly, sometimes they work and sometimes they won't; no rhyme or reason on which ones are acting up...they are programmed to open/close based on time clock programming and at times 4 shades may move properly, sometimes just 1, sometimes 2, etc. I go out and replace the batteries, but its still not working correctly.
I then upload the original programming but use the "force full upload" option, still flaky.
I then went into and exited activation and then performed a full upload, system has been solid ever since.