Meandering Towershell exiled with trigger on the stack.
Nope, that is a bug on Magic Online. The Towershell only returns if it's exiled by its own ability. If it's exiled by another spell or ability in response to the trigger (for instance, your opponent casts Path to Exile in response to the trigger), then it will not return during your next combat step, since the trigger did not exile the Towershell.
Nathan Long
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