Refi and Investment Purchase with One 30 day late over 12 months

[Matthew Swearingen]

I'm in the process of refinancing my home from a 4.65% to a 2.99%. My mid credit score is 657. I have about 150K equity. I have one 30 day late in Nov 2019 (over 12 months) I was told I cant get a loan (20 year-my current is 30 yr) and that I need to have it remove. It was a misbalance of funcs. My fault. I'm also looking at buying an investment home with 20% at 30 year. I have read and heard different things. My score is ok. I have good amount of equity, good income from job, very little debt and 20% down for rental.

Any help would be appreciated.