I spent some time analyzing the problem you have ran into. I tried to reproduce the issue but to no avail, just like I expected taking into account what you have said that it has appeared in <10% your devices.
However I think that I know what the cause is... My general conclusion is that your forms might be too complex for the devices you have been using, below are more details:
- Tecno SA6S is a budget device and has just 1GB RAM it's very little taking into account it uses Android 7 (for example some devices I have with Android 4 or 5 have more).
- In your form you use pretty complex calculations (maybe not complex in terms of difficulty but they are long what makes them complex - those used in columns:
calculationandrelevant).
So using forms with complex calculations on not very powerful device might lead to such problems.
I can recommend:
- please review your calculations and try to simply them, you can split them into a few smaller calculations. Here we had a similar problem with a complex form and such a trick helped.
- you can periodically reboot your devices like every morning to free up some resources
- you can ask your interviewers not to use those devices for other purposes, I mean not to play games, not to install not required apps (the same reason like above)
Unfortunately, it's not a thing that we could easily fix on our side. We have been improving the performance and probably there are still a lot to do but it's an ongoing process and it will never be perfect.