MO: DEfault Operating Unit Usage in 12.1.3 vs 12.1.1

Setup: This is our configuration for an AR responsibility for customer creation

- MO: Operating Unit at site level is null

- MO: Operating Unit at resp level is null

- MO: Security Profile at resp level is set

Process: I am opening the Details section of the Bill-To location (which displays the accounting flexfield combinations for Receivables, etc.)

Behaviour:

In 12.1.1, I'm able to view the account combinations.

In 12.1.3, I get an error for the DFF and Operating Unit (attached). This error gets fixed ONLY if I provide a value for MO: Operating Unit for the responsibility/site.

Is this an expected behavior change between 12.1.1 and 12.1.3?