OP sorry your YP is going through this. I hope you find a resolution.
I actually think too high expectations are placed on uni social life.
If someone isn't naturally a joiner, or introverted, or their face doesn't fit (or not white or ND or circumstances are they've accidentally joined an unpleasant houseshare or year group) the whole thing often can be fairly strenuous experience.
There's a lot of adults who are doing incredibly well career and life wise who hardly engaged with "uni social life".
Of course some people meet their partners or friend group for life. Especially if they're super extroverted.
But a lot don't. Or they get on the graduate job path and start making money and that's when their life takes off. Not everyone enjoys a houseshare environment!
I'd say focus on the basics rather than trying to force social things. Especially as I assume they're on student loans.
Get the good degree, put work into the next career move, don't overspend, don't get into drama, stay healthy, learn basic housekeeping, see it as a means to an end.
They may meet people naturally so enjoy those ad-hoc interactions.
Like pps say, there should be some activity or environment they can just drop into for a cup of tea and a chat. Chaplaincy can be good for this.
But if they don't easily find a friendly group, then I wouldn't force things or spend ages looking for the right one. It doesn't make their uni experience inferior to anyone else's.
Most people lose touch. No one gives a shit if you had the most fun parties in your first year.
If they.get their degree, get on the graduate career path and stay healthy that's all that matters.
If they've got a full week of classes that should take up enough time.
Maybe you could sub them Netflix or something. Or pay for a monthly gym membership. Something to ease things a bit.
But I wouldn't overthink the social stuff
(obviously if they're specifically being bullied then that's another situation. But not finding their tribe isn't an immediate worry).