I cared for my 4 surviving x-ray tetras in a 5.5g quarentine tank and treated with 4 rounds of flubendazole after loosing several fish to a probable gill flukes infection that proved to much for prazipro to handle. I let the DT fallow for 21 days and returned the fish, who were glass surfing and looking miserable in their tiny tank. I hoped that the flashing/glass surfing was a sign of stress and that a nicer home would improve things, but they are still unhappy after a day and a half to adjust. 
What is the best course of action? I am absolutely exhausted of trying to treat and retreat the dissease. I don't want to subject the fish to more discomfort. And they might be cured! It might be a stress reaction to loosing the other fish (different species, still tetras). They might just want some new buddies. Do I assume flukes and treat with a higher-than recommended dose of medicine? Do I let them be and wait to see if they start dying or adjust? I don't want to buy more friends when they might still be infected.

Prazi treatment was 3 rounds, 4-5 days apart, then another 4 rounds, 4-5 days apart, twice. Flubendazole was four rounds 4 days apart. Water parameters have been fine the whole time.

Unkillable flukes or residual stress?