Im having similar issues with the new update. I am fully able to import these .MXF (codec XAVC-L) however the files will lose contrast for 1 frame randomly which results in weird flash like frames. When moving and cutting the clips around the low contrast frame will elongate or move around. This has affected new footage and old footage shot on the same camera, same settings which was previously fine. It also renders out in both hardware and software renders. Ive tried in both media encoder and Premiere.

with footage shot on an FS5 mark II, these are the properties of one of the files with the issue:

Type: MXF
File Size: 117.75 MB
Image Size: 1920 x 1080
Frame Rate: 50.00
Source Audio Format: 48000 Hz - 24-bit - 4 Channels
Project Audio Format: 48000 Hz - 32 bit floating point - 4 Channels
Total Duration: 00:00:17:38
Pixel Aspect Ratio: 1.0
Alpha: None
Color Space: Rec. 709
Color Space Override: Off
Input LUT: None

MXF File details:
Wrapper type: MXF OP1a (type: SingleItem SinglePackage MultiTrack Stream Internal)
File generated by: Sony, Mem (2.00)
AVC Long GOP High 4:2:2 Profile 10-bit Unconstrained Coding
Bitstream Format: Sony
Class 50
Picture Profile 1

Examples of what I'm talking about. Just to reiterate these render in the final video!

I work with soccer videos, after I updated to 22.5 I couldn't import the .mxl files anymore. It has no imagem, only audio. GIve an e-mail and I'll send you the file for you to test.

Type: MXF
File Size: 716,67 MB
Image Size: 1920 x 1080
Frame Rate: 25,00
Source Audio Format: 48000 Hz - 24-bit - 4 Channels
Project Audio Format: 48000 Hz - 32 bit floating point - 4 Channels
Total Duration: 00:01:49:00
Pixel Aspect Ratio: 1,0
Alpha: None

MXF File details:
Wrapper type: MXF OP1a (type: SingleItem SinglePackage MultiTrack Stream Internal)
File generated by: FFmpeg, OP1a Muxer (57.83.100)
MPEG-2 422 Long-GOP