V15.1 SYOS Error?

Hello!

We are currently testing 15.1 in our test environment and discovered 
an unique error on TNEW 7. When there is a contribution in the cart and the user selects a SYOS event, the attached error is displayed. We do have a customization when a contribution is added to the cart, a MOS switches from Web (8) to Membership Web (27) to enable the member price types, but we have disable the customization in the mean time to troubleshoot.

The functionality works as expected in live (https://tickets.nyu.edu/donate/contribute1)
To experience the issue in test:
1. https://test-na-nyun.tn.services/donate/contribute1 then select an individual membership
2. Continue shopping and select Big Dance on 11/8
3. Select the section on the seat map and the error is displayed

What is also interested is the user can click the purchase Best Available Seating and tickets can be selected. 

We've been in touch with TN Support but interested to learn if anyone else experienced this issue or has any suggestions to resolve the error.

Thanks,
Joe