Clips out of sequence in viewfinder
 

I have a JVC GY-HM600 and have just noticed that a bunch of previously shot clips are now displayed out of sequence when I scroll through on the camera viewfinder. The clip numbers jump about, so for example clips 066-080 then 118-126 are displayed, then back to 081 etc

The clips play just fine on the cam and can be exported into the NLE, so I don't think there is a problem, just seems strange and certainly wasn't like this before. The clip dates are still correct.

What determines the order the clips are displayed?, I guess not the name or date.

I wondered if any other 600/650 users have seen this or have a solution?