We do experience the same issue with our integrations - but only some of them are affected. It seems to be a problem in the REST API oauth authentication, which is used by the Zoom LTI Pro App by itself.
We have ran across the status site of zoom:
“A subset of users not able to use oauth for authentication. -
Our monitoring has detected service degradation where Zoom’s Rest API mentioned below is impacted. Our engineers are currently investigating the impact and root cause. Zoom will provide updates as soon as there is more information to share.”
Hopefully it will get resolved soon.