Hello @BentonJohnson
Thank you for contacting the Canvas Community. We're sorry to hear you've been experiencing issues with calendar cache. There isn't really a "reset cache" option for the calendar specifically. It should be remembering which courses you have enabled and all events associated, meetings you've signed up for, etc. If you need to reset the cache it is the similar process from an internet browser and your mobile device:
In Chrome
On your computer, open Chrome.
At the top right, click the three dots
Click settings and then Clear browsing data.
At the top, choose a time range. To delete everything, select All time. I suggest at least 4 weeks
Next to "Cookies and other site data" and "Cached images and files," check the boxes.
Click Clear data.
If you are using the Canvas app currently we also recommend doing the same thing:
https://community.canvaslms.com/t5/Canvas-Student-iOS-Guide/What-Student-app-options-can-I-manage-fr...
Hopefully this helps!