I can’t imagine there being any difference in your scenario just because of COBOL vs NON-COBOL. (what is your former area that is “NON-COBOL”?)
If NON-COBOL is system software or Assembler, then maybe you are dealing with a different level of knowledge (read that as “lesser knowledge”) in your new position.
Sometimes , programmers who maintain these old systems are themselves quite young and do not have the background knowledge on how these old systems work; hence they are reluctant to even touch them. I have seen this many, many times.
One more thing I must point out … are the people you are now in charge of mad or angry about you taking this position?
My point is that it has to be something other than COBOL. COBOL is just a language. Nothing more than syntax. Application system design doesn’t change. Accessing data doesn’t change. Hardware doesn’t change. So it must be something.