I just loaded up a 8 tick Renko (ESU0) and it worked just fine. Loaded quickly and no gaps, etc.
Is it possible you had the wrong contract (ESU1) or something like that? That would explain the gaps in the data on the screenshot you shared.
If that does not work for you, I suppose you had better get in touch with Tech Support as I see it works perfectly on my end.
Thanks,
Donovan