Aunt or Half Sibling?

[Jlouise]

The other possibilities have been ruled out.

[Jim Barrett]

https://dnapainter.com/tools/sharedcmv4/1992 shows additional possibilities.

[Jlouise]

We are searching for my husbands father. We have a match at 1992cM. We were expecting this match to be an aunt however she has many matches that he doesn't share with her. I have sorted the matches. He shares the matches on her paternal side but none from her maternal side. We think she is his half sibling. Are we missing something?