Trimble R12i RTK base storing 2 files

I've never seen this before but recently the R12i RTK base will store a file for a while then at some point during the day it will stop that file and start a new one.  The receiver is empty, the battery is charged.

I wish it wouldn't do that, it messes things up.

I could try to figure out how to join the Rinex files in TEQC but really Trimble? You don't have a way to do that without an ancient command line program? Our ability to install software has been severely limited by IT, I get the concern in this modern age of abundant scammers but it does make things like this more difficult to deal with.