Infestation pandemic is not protecting “lswarm” monsters when activated in the chainlink. For instance I normal summoned evil swarm heliotrope using evil swarm castor’s effect, opponent chain link 2 activated conquistador of the golden land, I chain link 3 infestation pandemic, he chainlink 4’s torrential tribute. Master duel is resolving torrential tribute and destroying my evilswarm monsters who should be protected via infestation pandemic.
Based on how you just described it, its working correctly. Torrential Tribute will resolve first destroying the monsters, then CL3 resolves to make the monsters unaffected, but by the time thats resolving, the monsters have already resolved.
The chain resolves in reverse order of how it was built.