I am wondering if I am doing something wrong during the tunneler fight. As a healer, I know I have to cleanse the tank at 4-5 stacks but after I cleanse I am on a 30 second cool down and sometimes the debuff comes right back on the tank. There is nothing I can do during cool down so is this a bug or does the tank have to cleanse when this happens?

I posted this in flashpoints also but thought I might get a better answer here from a healer.

While the boss is channeling his ion cutter attack on the tank, every tick of damage applies a stack of the debuff, increrasing the damage of that ability. So even though you cleanse at 4-5 stacks, the tank is still being hit by that channel, so he will immediately regain stacks. Now depending on your tank, you can handle this different ways. if your tank is properly using their cooldowns, they should be able to mitigate a couple of those channels. Jugg tanks don't want to be cleanse when they have reflect available bc they want to use reflect as they get to higher stacks. Sin tanks can use shroud and stealth to deal with the beam. PT can use energy shield and explosive fuel.

As a sorc healer, i would suggest to bubble the tank as soon as the channel starts then you can cast resurgence>dark infusion>innervate>cleanse. at this point the tank will probably have dropped to about 50% hp, but you are cleansing closer to 6 stacks so they won't get to high stacks again. They otherwise shouldn't be taking too much damage in that fight so it is relatively easy to heal so long as you play around the beam correctly.

Keep in mind of course that these are random flashpoint pugs, so at least 50% of the time, if not more, your tank will probably have no clue what they are doing. you can try to explain to them what to do, or just heal through it if you can manage.

What gear are you at? When gear first reset I was having problems with the boss also despite doing the flashpoint for years. Depending on the tank, some are so good at using the cooldowns it feels I don't even need to cleanse/heal for 90% of the fight and I just damage. Other tanks who both used no cooldowns AND get hit by the droids aoe damage felt impossible to heal. Once I upgraded the gear enough though I've even been healing some groups that have fake tanks.

Other than that what the previous poster said is great advice.

Ez mode for healing

Afk / go grab a drink or something til you hear "targeting bla bla bla acquired"

Return to your keyboard and cast

Resurgence - Innervate - Expunge at 5 stacks - Force Barrier

Sometimes it's good to top off your tank with another resurgence - innervate again after the shield wears off.

Don't use these skills at any other time during the fight. Save them "Targetting bla bla"

If your tank finds other ways to get himself damaged or goes afk himself,

Just cast a random heal off your bar and consume darkness as you see fit.

If your tank is decent, in between lasers you can send your companions on missions, drop some cartel items to entertain your bored group members, engage in chat or whatever you feel like.

Cleanse at 5 stacks, force bubble, innervate healing rinse, repeat.

Also your cleanse should NOT be on a 30 second cooldown. Unless they changed that in the update.