Washing towels with bed sheets is not recommended.
Towels should be washed by themselves and not with other clothes or bed sheets.
Bed Sheets can be washed with some other clothes but you should not wash towels with your bed sheets.
When you wash your towels with bed sheets the towels could cause lint buildup on the bed sheets from the towels.
The towels could also bleed colors from the towels to the bed sheets.
So always wash your bed sheets separate from the towels and wash the towels by themselves.
Towels create a lot of lint which is the main problem when washing clothes, bed sheets and towels together so wash the towels by themselves to avoid the issues especially with the lint.