Steps to reproduce:

1. By default there is a default rank field named Rank
2. Add another customfield type Global Rank named Rank-1
3. Rank issue manually from Planning Board(both Rank and Rank-1) is working fine
4. Try to rank issue using Rank to Top using Rank is working fine
5. Try to rank issue using Rank to Top using Rank-1 is not working

Expected Behavior: as both Rank and Rank-1 can be used to Rank issue in planning board. Rank-1 should be working with Rank to Top features.

Workaround: This behavior is not reproducible using Rapid Board. The Rank to Top features is working for both Rank fields.