Put your best mods on each character and play it manually until you get everyone but Kanan out. I've had one time where I lost since I've been playing that mission. You also have to load up your Geo team in a specific way to best ensure Spy is doing the most damage. GBA, Sun Fac, Soldier, Poggle, then Spy.
Once or twice I've lost one character, and yes you can get stuck on Kanan, but at that point put it on full auto and let it roll. It'll finish soon enough and you'll be done.
Update: had to put it on auto basic to let the game end itself
Notes: -since 2pm cst, the game has been locked in this combat with a cycle of spy almost kills kanan and he instantly heals himself because of the debuffs on auto of sun fac
-spy is critting for over 500m and its not enough, kanan heals over 22m for every debuff
-after 650 stacks on spy, performance of the battle was impacted
Missed things: afternoon refresh, fleet payout period, evening refresh, preventing energy from not being spent after capping out, afternoon/evening/early morning store refresh
CG: you told us last week that you were going to be very careful about keeping daily playtime manageable with the 10th anniversary new features, and yet a single ROTE battle has been going on for 18hrs
Suggestions: -stacks accelerate, either we defeat kanan faster or he defeats us
-remove kanan, he doesn't make sense in the battle anyway (you can use nameless jedi battle 1 and mace led jedi battle 2). This is no longer a skill issue and simply a game loop that even on auto may never end or may end sometime tomorrow after power creep
-scale the battle for r6 because for some reason on an r6 planet you require r7 Geos