Hi, Kate!
I’m sorry to hear your dealing with this, I can imagine the frustration. I just spoke with our resident WPML expert and he gave me some insight into the issue your having.
For a translatable post type to appear on the front-end when WPML is active, it should have an entry in WPML translations table; since we do not add that entry the tickets do not show. When WPML is reactivated it will create entries for any translatable existing posts in its table thus making the tickets visible again.
The solution isn’t really that helpful as it also requires reactivating WPML to make sure the translation exists. The bottom line is that WPML is not compatible with the way our ticketing system works at this time.
If the above scenario isn’t workable then a few viable alternative to WPML would be Polylang (https://wordpress.org/plugins/polylang/) or MLPress (https://wordpress.org/plugins/multilingual-press/).
Let me know if you have questions or need further clarification. I’m happy to help 🙂
Cheers,
Trisha