Cap Gains on Primary turned Rental - am I wrong?

[Victoria Hartcorn]

Thanks in advance for reading. We are selling our condo and our accountant insists that we are not exempt from capital gains.

We purchased in March 2016 and lived in it 3.5 years until it was rented out for only 18 months January 2019 to June 2020, and now we are selling.

Since we lived there 2 of the last 5 years I emailed to confirm with our accountant we will not be paying capital gains up to 500k since we are married (she is a small business specialist who does our bookkeeping, payroll, and taxes for another business monthly). She said we are misunderstanding that rule and we will pay capital gains on the time we rented it out...

So, I am very confused about what the rule even means if I am misunderstanding it. I realize we will have depreciation recapture, but living there 2 of the last 5 years sounds clear to me.

If I am right, how do I bring this back to my accountant kindly? I obviously am not qualified to discuss taxes and I upfront pay for her services for the year, so I was hoping she could handle everything for us. We will be reinvesting gains into another property, so 1031 isn't out of the question, but we were hoping not to so that we can use some of the funds for other home improvements elsewhere. 

Any knowledge or advice appreciated. Thank you!