Not particularly. I take it that the SST is the shaft that comes with a Cue Tec.
Maybe it is the ferrule material used as some can be a tad more difficult to get a tip to stick to.
In my small little city, I tend to see my fair share as there are many players that use the Cue Tec.
I have never had one pop off as I tend to take a little longer to install a tip and prep them in a way that I hope gets them to stay put.
In the past, I have had Chinese cues with unknown ferrule material that have been a bit of a pain to get a tip to stick to.
In the absolute worst case, you could get a new ferrule of known American made material that would not give you any grief.
If you are currently having problems with yours, you could see if your repairman could take a couple of extra steps on the install. That may help.