Hard to say without a LOT more information...but there are the usual suspects...first is 1)safelights that are not truly "safe" for your paper! Safelight lighting can easily cause low-level fogging that leads to dull prints. 2) Is the developer at the right temperature? Lower temps make for much less efficient development 3) Are you developing your prints face-down in the tray, and PROPERLY agitating the print while it develops? 4) Are you developing your prints strictly by time--that is to say, for a FULL 60 seconds, or 90 seconds? Too-short development times can be bad, and cause dull-looking prints 5)Are you allowing for any "dry-down effect"? When viewed in the darkroom, under the proper examination light, a wet print often looks a bit snappier and more contrasty than it will once it dried, and is viewed in flatter, higher foot-candle lighting...6) Is your chemistry fresh, and properly diluted? Is your paper fresh, and in-date?
I think with good safelights, that are TRULY SAFE for the paper in use, that a somewhat longer development time of say 90 seconds, or even two full minutes,with the print face-down in the developer, leads to a slightly better overall image than a 60-second development time as standard...I just never felt that 60 seconds was giving me "everything the paper had in it". 60 seconds always felt too short to me...this was working under good,tested safelighting also. The face-down development keeps the image away from the safelight, and also more importantly, causes the darkroom worker to stick to the fundamentals of getting the right exposure on the right grade of paper, with the right dodging and burning, and working "by the numbers", and never being tempted to "yank" a print that appears to "come up too quickly" in the developing tray.
You might wish to test your safelight for 100%R safeness"--if the safelight lighting is fogging the paper, you will have only so-so prints!