Unable to Add Instantly Verification Column: Troubleshooting Needed

Can't add column to verify waterfall emails from Instantly. Before Clay subscription, I added one column for this and after payment I checked and it is working fine. But when I try to add a new Instantly column, it gives "failed to add column". I tried different methods, my team members tried creating one in their table, not working. We are creating this in tables that haven't reached the 72 column limit. Tried to add another enrichment column, it is creating example Apollo multiple columns. Only for Instantly verification - it is not allowing to create new columns. My Table - https://app.clay.com/workspaces/236286/workbooks/wb_AMYPQi5aWASs/tables/t_oTP27khKwGub/views/gv_Q57fABCfNWbr