Macro issues in f5 APM version 12.1.2

Hi DC Experts/All We are encountering difficulties with our APM VPE. Example: We have 5Macro. M1 M2 M3 M4 M5 M1 calling M2 M2 calling M3 M3 calling M4 and M5 Now M4 cannot call M5 because there is no Macro TAB in M4 but when I remove M4 from M3. I can assign M5 to M4 but cant brought back to M4 to M3.

 

Any ideas guys?