Recording stops randomly...?

Win 10, Cubase 6.5, using Steinberg UR22 MKII as soundcard. CPU is an i5 from a couple generations ago and using 16gb of RAM.

When recording guitars in a very simple project (almost no CPU usage) at 64 sample buffer rate, my guitar track is now stopping recording after about 100 bars. Not that it should really matter but this problem also occurs when you’re not playing guitar ie. just hitting record on the channel and letting it go for about 100 bars.

For some reason, there will be an audible click in the track and the guitar track will stop recording. The track continues to create a waveform/block/event in the track but no audio exists on it after it clicks and stops.

I’ve seen people say this can be due to low buffer size or other reasons. I need to keep the buffer size down obviously so I can play and monitor without lag. Any other things I should look at?

Update: managed to circumvent the problem (at least for now) by increasing buffer size to 92.