Rim fire Lugers are more function sensitive than many calibers because of the wide variation in ammo. Everything from cheap "bucket-O-bullets", hyper velocity, different bullet weights, target ammo, chamber cut dimensions and so forth.
Of the two most common .22 Lugers, Erma and Stoeger.....Erma seems to be more sensitive and prone to feeding problems.
Personally I always liked the Erma's solid metal toggle linkage over the Stoeger stamped linkage because it more accurately resembled original 9mm Lugers. Erma also offered longer barrel versions that looked like the Navy models. As for reliability, I love my Stoegers.