Thanks @Omnisciens, there are many reasons why an integration can break and all cases reported in the forum are unlikely to have the same root issue and resolution.
I think the best next course of action is to work with our support team (How to contact our Support Team ✉) to resolve your specific issue. Once you have found a solution, feel free to share what worked for you here, it will likely save other folks running into the same problem some time in the future!