One explanation I've seen:
Ratcliffe was to have given a report on the investigation of foreign influence in the election by the middle of December. That didn't happen. The report came in the day before the inauguration.
The report shows foreign influence.
Military has to vet all the research referred to in the report. Military has to determine, however, the CiC, which is a different position than POTUS, on inauguration day.
IOW, CiC is a military determination, POTUS is a political one.
Politicians decided Brandon was POTUS, but military holds Trump as CiC, as the verdict is still out on Brandon.
Military may be split, IMO. Trump mentioned the good generals he might name some day in an interview a month or so ago.
Look for Juan O Savin interviews from about 6 months ago. Whether you like/believe Savin or not, he explains his points very thoroughly, with background. He's good on the CiC issue, IMO.
Find an interview where the host let's him talk. He can take 20 minutes to answer an important question, and most hosts who want him on know this.