I get that you believe you know how the taunt effect for HT works. However your OP and following replies indicate you don’t.
Taunt will continually be reapplied to HT if Breach is present on your team. Yes, after 1 turn taunt will go away but it’s instantly reapplied if Breach is present on your team. Even if you manage to dispel HT’s taunt, it’ll get reapplied if you have Breach. This isn’t a bug, even if you believe it’s too much. If you reread the ability description, everything you’ve described is WAI.
There is no limit to its taunt, which is one of the reasons why HT is the best tank ship out there.