a typical pin capacitance would be 15 pf

T = RC

T = 15p * 10k = 150nsec to reach 2/3 of 5V.

I do not know how close to 5V you want to see, but 3 usec with a 10k before no noticeable difference from 5v is seen does not seem strange, especially if you have long leads to amplify the problem.

You might want to use 1k and shorten your connections.

Erik