The media is detected as XAVC-L type, and read using mxfxavc.dll - but I guess it's not the same to Sony's XAVC-L type.
General Name: A001C009_200914GX_C7000.MXF Folder: E:\TEST\Canon C70\120p Type: Sony XAVC Long MXF Size: 127.51 MB (130,573,872 bytes) Created: Saturday, October 17, 2020, 5:12:34 AM Modified: Monday, September 14, 2020, 5:45:14 PM Accessed: Saturday, October 17, 2020, 5:12:34 AM Attributes: Archive
Streams Video: 00:00:10.080, 25.000 fps progressive, 4096x2160x32, XAVC Long Audio: 00:00:10.080, 48,000 Hz, 24 Bit, 4 Channels, Linear PCM
Other metadata Regions/markers: no Command markers: no UMID: 060a2b340101010501010d43-13-000000-8aaaa4a5069105800000853079900057 Source UMID: 060a2b340101010501010d43-13-000000-8aaaa4a4069105800000853079900057
Media manager Media tags: no
Plug-In Name: mxfxavc.dll Folder: C:\Program Files\VEGAS\VEGAS Pro 18.0\FileIO Plug-Ins\mxfxavc Format: Sony XAVC / XAVC S Version: Version 3.0 (Build 14) Company: MAGIX Computer Products Intl. Co.
Also Sony Catalyst Browse have trouble reading this media: