Problems joining and staying in Cerberus/Baal fights

I'm having reoccurring issues with the Cerberus and Baal fights. Often, it takes me 40-50 minutes to actually join the fight after it begins. Other times, it will work for 5-10 minutes into the fight, then I don't get revived anymore. I'll try to refresh, but then I won't be able to get back into the fight. Clicking on the icon, or alert message will bring up a dialogue box, and it will read "Loading... 100%", but I will never make it back into the fight.
When things actually work, I do pretty well on the damage. I was #1 on the light realm for several fights in a row, so I often try to invest credits and gems into the fight to try to get in the top 5. But it hasn't been paying off for quite some time now.
Why can't I participate in these fight? Can I get back any of the credits or gems I invest if I get kicked out of the fight in the first 10 min?