I'd suggest a range of possible factors.
Pulling the print early is always a sign of a problem - give 90 seconds and adjust exposure and contrast, not the time in the developer.
The developer should not be colder than 20C as this will have pretty much the same effect as pulling the print out early. A couple of degrees over is not a problem.
Check your safelight and any other lights in the darkroom (light leaks round doors, red lamps on extension cables etc.) as any fogging exposure can interfere with the light you are choosing to squirt on to the paper. Even if the fogging exposure isn't enough to make a tone on it's own it will affect highlights especially.
How are you filtering? With a colour-head or filters? Confirm the values with the instruction leaflet in the pack of paper.
Use stop bath (as recommended by Ilford). Paper carries over far more developer than film and remember that water-bath development (google it) was once a way of reducing contrast. Developer carryover will also quickly kill your fixer.
Thirty seconds in the fixer is the minimum time at a minimum temperature of 20C. Where you are using easy-to-wash RC paper you can safely allow a little more time and give constant agitation. Be very certain that you are using a 'rapid' fixer at film-strength (1:4 for Ilford Rapid) and not the older hypo-fixer (in either case you would need a much longer fixing time). Under fixing isn't going to help the print in a few years time . . .
Read Bob Carnies enlarging thread,
(there was a url link here which no longer exists).
For this particular neg, there is tone even in the jumper so you should be able to get that barely visible in the print too. Start with Grade-3, take a stop and a half off the exposure you previously used (remembering to also allow for the speed-change across grades, if you are using filters), to see what you can do with the subjects face, it is where everyone looks in any portrait, adjusting time until the face looks ok. Only then adjust the contrast, if necessary, to change the darker tones towards where you want them - additionally the dark jumper and jacket could be burnt in with grade-5 a little, in order to make the darkest parts go just to black for example. The plain background might also want slight darkening in the corners, for example. Remember that you can add tone and black by burning in, with appropriate filtration, so the basic exposure is the one that just gets you the starting point of (for example) the face - of course, sometimes it is more practical to dodge a small area than to burn-in, it depends on the scene.
Make notes of everything which you are doing. You can usefully make a short series of prints of the figure, with half a sheet of paper centrally, at grades 1 to 5 while adjusting the time to keep the face about the same tone. It will help you as a comparison for your next test-print to suggest the direction for you to adjust in.
I have no clue what I'm doing, so read what everyone has said.
