Because???
Is that the only code in the app?
Translated with Google
@jared I moved this piece into a clean app to check for interference.
@actech I uninstalled it and installed it two or three times on two different phones only once for the first three translations did it seem to work (coincidences?) Then it started to make mistakes, the other times and on the other phone it never gave the right result.
I also tried downloading the android app but it doesn’t work.
Can you give me a link for test this project?
I understand part of the problem, I have to click the button 2 times.
It seems to remember the previous result, but I don’t understand where the first result comes from if I start from a new installation (by clicking several times on the same word from the second onwards the result is always correct)
I tried to delete the contents of the label but nothing changes.
You are right! I see problem!
I think the following is actually happening. The block where the string length is calculated is performed later than the block where the new string is written. For this reason, the length is calculated from the old string, as you correctly said.
If you delete the length of block, you will see which row is assigned in the label laEnglishCounter.
This is a bug!
Temporary try this bad solution.
Thanks, it works! 
There is another more reliable, but also more complex solution to this bug. You use the timer to check whether a new word has been translated. If it happened, then run the blocks further.