Ok. I did some test. It seems that we have a defect to solve here.
Your use case can be even simplified (I just created a type “B” with a predicate “in” with @reverse.
I declared B with in and ~in predicate. and 2 nodes <0x1> in <0x2>
Expand all works on 0x2 and follows the reverse. expand with filter does not.
The defect is reported as an issue in our git repo. Add other filters to expand() · Issue #5803 · dgraph-io/dgraph · GitHub
Could you have a look and add a comment with your case. We will set a proper priority to this old issue.
In the meantime is it an option for you to explicitly write your predicates and reverse predicates (instead of expand(all) in your queries ? or write the behavior of expand in your go client at least for the part using filters on a reverse edge : building your DQL query string based on the schema and repeat the block for all predicates and reverse instead of expand(all) ?