The english sentence should specify if the student is female or male, so we learn to use the proper word. Otherwise, don't tell me I have a typo.
Simply flag it and report "My answer should be accepted."
The course contributors need to manually enter all of the different answers to each sentence individually. There are bound to be oversights.
I wrote: 'Discipulo bene scritit.' and it corrected, "Discipula bene scritit." So what is the masculine nominative singular? OR: What if it's a male student doing the writing?
"The [male] student writes well" is "Discipulus bene scribit".
I think the correction algorithm provided you with "Discipula bene scribit" because "discipula" is closest to "discipulo".
discipulus declension table
discipula declension table