fecc1be23143476b981352e8516cf9cce0450d62 changed the default addresstype, which means that functional tests that create tx sending to short scriptPubKeys such as OP_TRUE might violate the "tx-too-small" policy rule. See the added TODOs in the functional tests in that commit for reference.
The TODOs can be solved by defining a large enough dummy scriptPbuKey (maybe as a constant, 64 bytes should be long enough) and using that over OP_TRUE or hardcoded in-line CScript([b'a' * 35]).