@Jevani P. Barron I would only consider selling if the gain would allow me to buy a better property with considerably more cash flow.
Long term rentals typically require much less work than a fix and flip. If you’re looking for a more full time job I’d consider that. If not I’d consider staying with the rental and raising the rent to market rate at lease renewal in May.
I’ve had about a 60% turnover on units that were under and I’ve brought current. The other 40% realizes it will cost a lot of time and effort to move and that they’ll likely be paying even more afterwards.
Since the tenant has been there a long time your market rent will be less than market rent for a newly renovated place which should be a consideration of the tenants.
For instance I’ve got a building that still has 3 unrenovated units. Fair market rent for these is $800. The other 4 similar units that have been renovated fair market rent is $950.