NextGen / The Events Calendar JSON error

There is a conflict between versions of NextGen Gallery and The Events Calendar starting with NextGen Gallery 3.3.0. We’ve been forced to update to 3.5.0 due to security concerns so our website is currently broken. Entering an event in The Events Calendar while NextGen Gallery is updated to 3.3.0+ causes a JSON response error to be thown. Creating a new event results in “Publishing failed. The response is not a valid JSON response.” Updating an existing event results in “Updating failed. The response is not a valid JSON response.” Creating a new non-event still technically works, as the event is created, but the error is concerning, and creation of recurring events does not work in that only the first event in the series is created. I have done extensive testing, deactivating various plugins, and assure you I have narrowed this issue down to versions >= 3.3.0 of NextGen Gallery. Anything less than 3.3.0 and no error is thrown in Gutenberg or Classic Editor. Using Classic Editor is not an option, however, because a) it won’t be here forever and b) it does not allow for proper editing of recurring events. A search for the error message and NextGen returns all kinds of result of people experiencing similar issues with The Events Calendar and other plugins. Many suggest Classic Editor as a solution (which didn’t work for us), or updating permalinks (which didn’t work for us). Help?