Denied for a Heloc? Still not sure why?

[Kenneth Morff]

Hello, I don't post on here very often, but I'm not sure where else to turn. We just got denied by a Bank in Saint Cloud. The property we are looking take a Heloc out on is in Sauk Rapids, its worth about $170,000 We own it for $81,000. The banks reasoning was that my credit score is kind of borderline (660), we have purchased too many properties to quickly, and it raises flags? They said I should just wait 9 months to a year and reapply? 

Is this normal? I have purchase 6 properties since 2015 we sold 2 a profitted from both, so we own 4 rentals. I asked if my credit was better would it help, she said it won't help, I just need more time?

I would prefer interest only, it keeps expenses down for more lending.