For a language-specific thousand separator I tried to enter a single space in the translation list, which was not possible. Neither as single space nor as non-breaking space. Together with the support team we tried different ways, but Passolo always removed the single space, so that in the end the cell was empty. I did not need an empty cell but a single space...
The support finally found out that in order to enter a single space, you have to disable the function "Transfer white spaces at beginning and end of source text to translation". Then it is possible to enter a single white space without trim.
Personally I think this is a software bug, but the support told me to put this here as a suggestion because there is a workaround.
Since I doubt that I will still think about this in a year or so, I would like to see that one can enter a single space without temporarily disabling this function.