With previous jobs they changed the schedule without telling me and when I didn’t show up they weren’t mad, they took the blame. However, Starbucks does things differently than most jobs I’ve had SO I can not say for sure. I’d say just ask your manager

Technically after the schedule is made they are not allowed to change your schedule without asking you first let alone change it without telling you.

4 year partner + SS here.

I know before the teamworks app they had to in some way notify the store of an "updated schedule" posted in the back. However I think something changed when teamworks came along because this has been happening to pretty much everyone in my store since then. Especially with my store manager being the one to train all of the SMTs (store managers in training). So they always screw up the schedule somehow and have to change it like 3 times after they put it out.

HowEVER this is also why they're supposed to have 3 schedules out ahead of time to counter this issue. That way if someone has made plans before the change happens, they're supposed to work with you to help resolve the issue.

Also I know good managers are very far and few between so I'm sure most of them just say "oops well look at that I forgot to schedule a keyholder for 30 minutes.... guess I'll just make (random SS) stay an extra thirty minutes next tuesday."

I don’t know if there’s any written rule about it so someone else please speak up, but any changes made to the schedule need to be told to you. Your managers seem to be having a lack of communication and you should bring it up to them.

That has never happened to me. I've been asked if I'm okay with an upcoming change to the posted schedule (and I've at times accepted the change, at times declined it), but it's never just happened without notice. I'd say that's not respecting a partner's time and work/life balance.