Possible Causes, Possible easy solution
Not familiar with the Hi-Power (wish I were) but it looks like it has essentially the same firing pin arrangement as the 1911. The conversion kit probably is similar.
So, just some sugggestions which may or may not be appropriate, depending on the mechanism.
Possible causes:
(0) Slide not fitted to frame properly or too long, so that the hammer does not strike a straight blow on the firing pin.
(1) Excessive headspace. The .22LR should have a headspace of .044" to .046". A talented amateur mechanic can measure this with a bit of ingenuity. (NOTE: insufficient headspace will result in slamfires, excessive headspace will result in misfires.)
(2) Firing pin too short.
(3) Too much of or too thick an oil, or dirt on the firing pin spring or in the firing pin channel. This may soften the blow of the firing pin against the rim of the cartride.
Three is an easy fix, which you might try before sending the gun back or bringing it to a 'smith.
Get a pair of goggles and a magnet.
Remove the firing pin and spring and make sure they are clean and not oiled excessively. These parts require only a tiny amount of oil, which should be very thin. One way of doing this is to put a tiny amount of Hoppe's on your rubber-gloved fingertip and rub it lightly on the clean firing pin and firing pin spring.
Make sure the firing pin channel is clean as well.
The firing pin on the 1911 is spring-loaded toward the rear and releasing the retaining clip (extreme rear of the slide) can result in the pin and spring jumping out of the gun.
The firing pin sticks out from the retaining clip slightly thereby holding it in the slide. Depress the firing pin with a small piece of wire or other implement until it is below the retaining clip. The retaining clip can then be slid out of the slide. At this point, unless you have covered the rear of the slide with your hand, the firing pin and spring will jump out. (The hammer strut is often used for this operation, but it is unnessesary. A paper clip will do.)
The goggles are to protect your eyes if the parts jump out unexpectedly. The magnet is to find these two pieces when they fall on the floor. But it helps to point the back of the slide toward a wall while removing the firing pin retainer clip as well as hold your hand over the back of the slide.
They also have a tendency to seek freedom while you're reinstalling them.
Over the years I've lost two firing pins on this account. The first one was because I didn't know what I was doing. The second one was because I'm a slow learner.
For what it's worth in your case. Hope it helps save a couple of bucks for you.