...am using a Lookup for the student names and a lookup for the university names...
...It works fine when I set it up on a non-lookup field.
Sounds like you are saying the table is where the lookup field is. If so, then unless you plan to work directly in tables (which isn't always a great idea) table lookup fields should generally be avoided. The main issue is that the value seen is of course a value from the data source, but what Access stores is the index number for that value. Possibly that value can be used when the lookup is based on another table, but when it's a multi value field, the index is hidden and you cannot get at it.
Sticking with the assumption you have a table lookup field, you may have to use the .Value property to retrieve the actual value that you see in such a table field. However, I've never tried to access that in a form control record or row source - only in a query. Sorry if I'm way off base, but "doesn't work" doesn't reveal anything of value. In this case you could mean you get the idex value (a number) or nothing at all, or maybe even an error.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.