SeaMonkey 2.49.4
Waterfox ~56.2.7.1
FreeBSD-CURRENT
I'll add a full screenshot in a separate comment.


I sent an e-mail to Scroll with reference to this issue.
Firefox 65.0.1:

On closer inspection, it's not just the table of partners.
The _coalition_ table is not visible. Waterfox, safe mode:

Thanks for the bug report 👍
@wisniewskit can you please take a look at this one?
I can confirm that Firefox 56 also had the issue, but it isn't present on Firefox anymore (including ESR 60).
My immediate guess based on the symptoms is that it was fixed by bz958714, and while mozregression couldn't pinpoint a fix for me for builds that old, the range it did give me does contain that bug, so that's what I believe is the problem.
Since I believe Waterfox is still mostly based on Firefox 56's codebase, that would explain why it's still happening there. If it's possible for Waterfox to backport that fix, it would make them significantly more interoperable with respect to flexbox.
@grahamperrin, would you be willing to contact Waterfox's dev team and let them know?
Great! Thanks for mozregression and analysis.
I raised the issue as a bug in the Waterfox repo (link above); and I have a mental note to alert someone in the SeaMonkey area.
This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue at https://webcompat.com/issues/new if you are experiencing a similar problem.
Most helpful comment
I can confirm that Firefox 56 also had the issue, but it isn't present on Firefox anymore (including ESR 60).
My immediate guess based on the symptoms is that it was fixed by bz958714, and while mozregression couldn't pinpoint a fix for me for builds that old, the range it did give me does contain that bug, so that's what I believe is the problem.
Since I believe Waterfox is still mostly based on Firefox 56's codebase, that would explain why it's still happening there. If it's possible for Waterfox to backport that fix, it would make them significantly more interoperable with respect to flexbox.
@grahamperrin, would you be willing to contact Waterfox's dev team and let them know?