Trouble connecting to shared drives over our home wifi

[silobass]

Mrs S works for Public Health England and they have shared drives that she has to access. Since we've got a new modem from Virgin at home, she can't connect to them via our wifi. It does connecting when using a cable. When she's at the office everything is fine on wifi but at home it doesn't work. Everything else in the house works fine.

Any ideas what might be causing it?