Dear list,

while doing some math typesetting, I have found the following features not
working in LMTX:

1. Non-displaystyle operators are simply not shown (try \sum or \lim in text or
   scriptstyle). This works in MkIV (and iirc in LMTX versions from before
   november).
2. \underbrace{x}_{y} stopped working. It produces an underbrace but the
   subscript is not centered below the brace. It will show up as right
   subscript. This works in MkIV.
3. \startformulas does not allow numbering formulas because the number will run
   into the next column. I have posted this at

https://tex.stackexchange.com/questions/518262/context-number-formulas-side-by-side
   and Henri Menke tested that it broke in 2017. Aditya Mahajan mentioned that
   it is a bug.

For the upper two cases: Is anything wrong with my LMTX installation or did I
miss some upgrade instructions for math in LMTX?

Many thanks for an answer.