The bug appears to be that the mana bar did not drop. Poseidon grants a resist to new effects. But this isn’t a new effect, and so it should not be getting resisted. Therefore the effect should be able to lower the mana bar as normal when the effect procs.
Best bet is to submit a support ticket, so that SG can take a look at the case. I’ll let staff know that there appears to be a bug here, and to expect a support ticket.
