There is nothing wrong with printing at Grade 5.
But if you are like me, and like your negatives to print well at Grade 2 or 3, then you have to make your negatives higher in contrast, meaning you need to develop them longer. I suggest starting with adding about 12% and go to 9 minutes, print a couple of frames and see what happens.
I like to be able to have wiggle room when I print. Most of my negatives print well at around Grade 2 to 3, but sometimes I want a bit of extra punch to the print, and I use the Grade 4 or 5 filters to either burn in certain areas, or give the whole print the high contrast treatment.
If my negatives were such that my 'normal' print would be at Grade 5, and I needed more contrast, it would be very difficult to do.
Just something to think about. Increasing or decreasing negative contrast is a basic control point of your process, so look at your negatives critically, and adjust developing time as necessary so that you can print at your preferred contrast grades. It's entirely in your hands.