Hi,
when you define a custom request you get to define the response too. And sometimes (sadly) the responses change between IFS updates.
For example:
Did you copy paste the response from the IFS cloud (Stage) as it is now?
If that didnt work then i guess the problem could be in this specific response:
(Flow REST connectors dont like arrays without column names)
If you dont care about the response maybe you can try to set the connector Break workflow on error: No
If that also didnt work then updating the OData connector would be your best bet.
Other than that you could just make the OData call with defining the regular REST connector (there you can handle arrays without columns like in this post Error message importing a REST configuration - #2 by OlaCarlander) but…that may be more trouble than its worth 
Hope this helps!
B R
Ivan