OK, assuming same contrast filter and same f stop on lens, the print should come out at the same density as the test strip, so something is wrong.

Q. Is it the way you are using the test strip? lets say you expose 1/6th of the paper for 5s, then a second strip for 5s making a total of 10s, then a third strip 15s, 4th 20s, 5th 25s, 6th 30s. Are you by any chance thinking "I'll take strip #2 which was the 10s strip", because of course this strip has been exposed for 25s, i.e. the whole exposure time less the first 5s.

Also, I presume you aren't changing the height of the enlarger between test strip and print?

Also, you are leaving the print in the dev for long enough. It does take a little while after the image first appears to develop properly

By the way, #2 is quite soft. You might like to try #2.5 or #3 as well.