Faced the Ghost gym on the Complex Gaming server, using a team that included a Shedinja with a Focus Sash. The rest of my team had fainted, but there were still several enemies left, each with Ghost moves, including some with Shadow Sneak.

However, each of them used a random move, as if they didn't have anything that could hit Shedinja. I suspect that it saw the calculation for damage saying even the super effective move would do 0 damage, and so picked a random move instead of the super effective one to break the sash.

This is the Pokemon, moves, and items on the Gym Leader's team. Shedinja killed all but Drifblim and Gengar, as they kept picking moves other than their ghost moves.

Gym leader team = https://ibb.co/QMy3nhP

It appears that the AI recognizes Will-o-wisp/toxic as able to kill past the sash, but the normal attacking moves do not get recognized.

Had an E4 trainer with Cloyster use Rock Blast to kill a Volcarona, but then it switched out when shedinja came in.

The Ditto it switched to used will-o-wisp to get around the sash.

Hi,

I can confirm that this issue still exists in the latest 8.3.6 release, trainer AI will not prioritise super-effective damaging moves against a shedinja with a focus sash. The AI used seemingly random moves, but when given will-o-wisp the AI will consistently use it, so the status moves appear to be recognised as able to damage the shedinja.

This should be moved to the internal tracker soon. Thank you for your report!

Forwarded to the internal tracker, thank you!

I can confirm this is fixed in the latest 8.4.0 release - thanks for the report!