The only thing less reliable than their 9mm is the .380 as it uses the same magazines. Same core problem plus being called good enough for a rather different cartridge. The 9mm carbine uses a different magazine than the pistol and the .380 carbine uses yet another magazine where the .40 and .45 carbines use the same mags as the pistols.
Big numbers, the carbines of any caliber run the best. By Hi-Point's own admission, the .45 carbine is the least accurate. If I had to have one of their pistols and it had to be reliable rather than an inexpensive range novelty, I'd opt for one in a caliber starting with 4.