The old ZCOMBO devices (fw 0.5) won’t ever go to Complete w/o you physically waking them up. So yes, they will stay in ProtocolInfo forever. These devices just don’t ever perform a Z-Wave Wake Up, which is required to finish the interview, and is what your other battery devices are doing.
My theory is that you have some issue with the cache file. Corrupt cache files are pretty rare these days though. I can’t say for certain, but I was hoping the debug logs might give a clue. If the file was corrupt, the log would say that.