Source on GitHub
Testing and Issues
You can test this app and submit issues during the testing period of the Android Contest 2021 contest.
Entries with serious issues will not be able to win the contest, but even minor issues might be important for overall results.
1) Partial fix of a bug with updating reply message: https://bugs.telegram.org/c/179 (by "partial" I mean that only one part of this bug was fixed)
2) Fix of the dark themes bug based on the provided suggestion: https://bugs.telegram.org/c/923
Full description: https://github.com/sfilmak/Telegram/blob/master/SubmissionChanges/report.md
Video showing issue with the first solution attached to the next comment.
editingReplyObject.forceUpdate = true;
You can see where exactly it should be placed in the code on a screenshot. It seems to fix the bug completely, but if you will found any other issue with my solution - please let me know in the comments here.