7. Deactivate your PC Anti-virus software provisionally
Anti-virus always gives restrictions to you to run different application software. Many of the cases, it has found that Anti-virus restriction is the core issue of Discord screen share unavailable problem.
In this case, you should disable your Anti-virus to run the Discord screen share app and contact your anti-virus software vendor to inform this issue to affix or change your anti-virus software.
After all of these, if you find Discord screen share, no audio problem, then move to the following procedure.