Everything besides CSGO competitive matches record properly, whether that is casual or custam matches it will record fine. Play.tv also records other games properly with very little failure, yet for some reason competitive trumps this service
Are you using a different client or add-on in regards to Competitive Matches?
However, it might also be timing out due to mis-matched detection.
If so, I'd recommend making a ticket with logs attached.
To send logs you just right-click on the Plays.tv taskbar icon, select Help > Feedback, fill out the info and make sure the checkbox is selected. Post back here to let me know you have sent it.