Missing frame and turn black screen

Hi, I am facing problem in Davinci Resolve 11.3. The problem is just like the photo I show below. My clips just disappear and turn to black screen while I playing the clips. They should come out with the screen I shot but there are BLACK SCREEN. The camera model I used is AG-HPX250 P2HD Series-Panasonic.

Anyone facing the same problem also? May I know the solution?

Ya, actually I have another Mac is in resolve 12.5 version but still facing the same problem.However I have figure out the reason. It is because davinci resolve can't communicate with MXF file which is long record. So, my only solution is one by one force link to media pool and just recut the screen I want but I feel it is abit stupid. Do you know any other solution?