If your film exhibits poor contrast you develop longer and you may want to consider agitating every thirty seconds.
HP5+ and Tri-X are not identical, but every time you switch films you have to recalibrate how you do things, to make sure your negs suit your work flow, and that's what film developing is, a part of a whole, or part of a system, as an intermediary to carry information from the photographed scene to your paper.

So it's your job to make it work, since it's your work flow. Bracket your exposures, alter developing time, change agitation frequency; all these are tools at your disposal to fix any problem you might have.