Home office deduction

If you are an employee that receives a W-2 then none of your employee business expenses, including a home office, are not deductible on a federal tax return due to the tax code changes in effect for tax years 2018 thru 2025.

if you can answer yes to the regular use question below, it would seem you should have gotten the HO deduction. we have no access to your return so you may need to revisit the section:

is the area used for business used on a continuing basis?

Occasional or incidental business use does not meet the regular use test, even if the area is used for no other purpose.

it may also be that you have run out of deductible HO expenses. after 40 years the office would have been fully depreciated and it's kind of doubtful that you had a mortgage interest deduction. taxes would have remained deductible. the deduction for other expenses could have been limited.  

If you made so little you might not be able to take the home office deduction.  Some expenses, such as home office or section 179 depreciation can only be used to reduce your schedule C taxable income to zero, and not to create a loss. Excess deductions for these carry over to the next year.  And you have to answer yes to both questions about exclusive and regular use, not just one.  The area of your home office must be used regularly and exclusively for business to deduct it.

Or you checked the box on 32b saying Some Investment is not at risk.