As far as I know they have never displayed on the Piano Roll.
I am referring to the Staff Roll Notation Mode.

In The Notation Window for a MIDI track, from top left you have;
Options Button, Print Button then the three display option buttons;
1. Standard Notation Mode
2. Editable Notation Mode
3. Staff Roll Notation Mode
All three options display Sharp, Flat and Natural symbols to left of the note in RB2019 & RB2020 32bit but only options 1 and 2 display these symbols in RB2022 64 bit.

Vintage