I have just reported: אני הולכת לפגוש אותו בשוק
Same. I cannot understand why it isn't included among the options.
I did the same but I am afraid they do not care about our reports here
why is "להיפגש איתו" wrong in this case and when would it be used?
I think it should be accepted. There is a slight difference in the meanings of לפגוש and להיפגש: usually, להיפגש means by design, and לפגוש could be by chance.
Would it be correct to think of it as 'I'm going to meet' for להיפגש and 'I'll meet' for לפגוש?
As far as my hebrew teacher told me, להיפש implies a meeting, even something official, while לפגוש could be something short or unexpected or anything that you wouldn't call a meeting.
Can this not be interpreted as future tense? This was marked wrong
אני אפגוש אותו בשוק
I would translate your Hebrew sentence as "I'll meet him in the market" which is different from the original sentence. You shouldn't overthink it. Hebrew tenses are much simpler.