I am using newest Fluent 2023 R2, acad. vers. and I can confirm that the bug is still unsolved.
I have screen resolution 2560 x 1440 and attempt to write video leads to error "Input file too small! (??????) Removing frame files ... done."
After changing resolution to lower 1920 x 1200 is video created as expected.
Please, report this error to developers to solve it as soon as possible. Thanks in advance!