MPEG-2 Blu-ray extras lose 16:9 aspect ratio after MakeMKV remux (DAR becomes 1:1)

[ntropy]

I am encountering a reproducible aspect-ratio issue with MPEG-2 Blu-ray content after remuxing with MakeMKV (tested with 1.18.1 and 1.18.3 on Windows x64).

Source (disc playback / elementary stream):

MPEG-2 Video, 1920×1080, 29.97i (Top Field First)

Display Aspect Ratio correctly signaled as 16:9

Plays correctly in MPC-HC directly from disc

After MakeMKV remux to MKV:

Video dimensions remain 1920×1080

MediaInfo reports:

Display aspect ratio: 1.000

Original display aspect ratio: 16:9

Some players render the video horizontally squeezed unless the container DAR is manually corrected

This affects short-form Blu-ray extras (e.g., “Production Notes” text-on-graphics), authored as interlaced MPEG-2. The video essence appears intact, but the 16:9 aspect signaling is not preserved at the container level.

This behavior persists across MakeMKV versions, suggesting a limitation or design choice rather than a regression.

Question:
Is this a known limitation of MPEG-2 → MKV remuxing in MakeMKV, where the MPEG-2 sequence header AR is not explicitly propagated to the MKV container? If so, is external DAR correction the intended workflow for MPEG-2 Blu-ray content?

Specific title export is The Abbott and Costello Collection- Disc Nine_t06.mkv

[dcoke22]

I've seen people mention having a problem like this, but usually in the context of a DVD not a blu-ray.

https://forum.makemkv.com/forum/viewtopic.php?f=8&t=19234

I don't know if it is the intended behavior, but it seems relatively easy to correct after-the-fact with MKVToolNix.