Yup the prices are awesome, an amazing bargain.
Yeah I found issues with the batteries at first. I've only used Samsung 25Rs in mine (which are you using?) but whereas in my Waidea Flask they dropped right in with loads of room to spare, with the SXK I had to really push the caps down hard while turning to get it to bite on the thread. It would then screw down tight (but the caps never line up, sadly) but it took some effort - I generally used a screwdriver rather than coin, and couldn't do any part of it with my fingers.
The good news is that it loosens up over time. I can now push down the cap with my thumb while giving it a half-turn at the same time and grab the thread every time. So those springs do loosen.
Which flask do you have, black or silver? Be aware that you may have grounding issues - there's been lots of discussion on the VF Clone thread, and you might want to scroll through the last 10 pages. If you have silver then more likely than not you'll be OK, though there has been one report of problems. If the black, more likely than not you'll have problems.
The fix is to remove the top plate, and then sand down the underside of the top plate and the top of the flask on the "mating area" - ie the area where those two touch. Sand it down or dremel it down, then clean the area thoroughly (ideally with IPA). Ditto clean the battery threads thoroughly, with something abrasive and then IPA. That black coating affects the conductivity, often leading to batteries draining unevenly in the case of the threads, and grounding issues in the case of the top plate.
Symptoms include shutting down randomly, saying Low Battery when it's clearly not, or sending out less power than it says it is. In the most serious case people have had it reading 0.00Ω and saying Low Res whenever it tries to fire, but clearly yours isn't doing that.
You may not need to do any of that right now if you have the Silver, but look out for the symptoms. I had none of those problems with my Batch1 Silver, but
@dwcraig1 got a Batch2 silver and he had the low-watts issue which resolved after sanding.