We have faced a problem with using REST sender with client credential flow and when investigating it was found that the problem is with the token fetching request.
IFS is sending client id and secret in two places, As basic authentication in the header and the url encoded request body.
Seems sending the client secret in the body is faulty.
Is this a bug or is there any workaround to not to include the client secret in the token payload.
Issue was found in IFS Cloud 22R2 but we observed same problem in Apps10 UPD 16 as well