Report a bug

I think this is a bug, because when I ask string.sub({wsr},0,2) on Samsung it gives '06' and works, on Huawei it gives '6:' and of course doesn't work. When I ask string.sub({wsr},0,1) on Samsung it gives '0' and doesn't work, on Huawei it gives '6' and works. It's not normal it gives a different result on 2 devices.
When I try the same with {wss} there is no problem using string.sub({wss},0,2) on both devices.