Issue importing XAVC-L HD mxf 50i with the import window

Sorry for bad english.

We had a Sony PXW190 camcorder during a brief test period and I encountered difficulties during the import. The format chosen: XAVC-L 50i FHD MXF. The other formats being optional ... Firmware in V2.
Tested on FCPX 10.4.6 High Sierra, FCPX 10.4.8 Mojave. Last pro video format for every OS ( not sure, something like 2.07 and 2.1.?...)

No problem if we import from the finder.

The difficulty arises when importing via the FCPX import window.

1 - the display of thumbnails does not necessarily correspond to the video
Randomly and systematically, several thumbnails take up the thumbmail from another video. video 1 ok, video2 ok, video 3 shows the thumbnail of video 1, etc ...
2 - more serious and therefore blocking, randomly and systematically some imported files defects in shot length. Example, for an 8-second shot, the audio lasts 8 seconds and the video doubles it (with a still image from 8 seconds which "lag" with skimmer ).

The camcorder having left ... Is anyone able to confirm or deny this or better indicate a solution with the import window ? We can't test anymore. We doubt

Thank's

It's maybe more simple if I ask like this : do you have any issue importing XAVC-L with the import window ?

Thank's.