The DVR is behaving as designed - splitting on silence. The best option is to turn off "Split on silence" and manually set a recording duration (taking into account the duration of potential ads).
Split on silence:
https://applian.com/replay-media-catcher/support/user_guide600#settings-dvr
Manual duration:
https://applian.com/replay-media-catcher/support/user_guide600#guide-digital-video-recorder
Alternately, one could recombine all of the recordings afterward.
https://applian.com/replay-media-catcher/support/user_guide600#split-and-combine