Since their offices were (still are) closed during the pandemic, both of my sons have been working from home. To date, neither has used a home office deduction. Assuming they have a dedicated space in their homes, is there any problem claiming a home office deduction?
Your question seems to suggest that your sons are employees. If this is the case, then a home office deduction is not available, even though they have no alternative but to work from home while the business has closed its offices. If they are self-employed, then yes, they may be able to claim a deduction. Information on this page may be helpful: