Important

Problem — The chat markdown renderer's guarded single-$ inline-math rule rejects any math whose opening $ is immediately followed by a digit (a currency false-positive guard). All digit-led inline math — the single most common physics reporting shape, e.g. $3.53\times10^{-5}$, $10^{-5}$, $F = 0.99$-style values starting with a number — falls through to markdown and renders as raw text. Non-digit math ($\alpha$) renders fine, which is why the failure looked random.
Approach — Move the digit guard from the open side of the delimiter to the close side: the opening $ keeps the no-space/no-$$ guards but drops the no-digit one; the closing $ additionally must not be followed by a digit. This is Pandoc's actual currency rule ("the closing $ must not be followed by a digit") and it holds every existing guard case (tight pairs like $30-and-$50 stay literal because the first closing $ is followed by a digit) while letting digit-led math through.