I'm inclined to agree with the comments of 1911toGlock & mrsurfboard.
I've seen all manner of folks experience some occasional issues when shooting smaller & lighter .45's, both metal & plastic-framed models.
Generally, as an instructor and an armorer, I can't really disagree with the oft-heard observation that as .45's become smaller & lighter, they can become less tolerant of both shooter & ammunition influences.
Shorter slide travel, reduced slide mass, recoil spring assemblies using shorter & heavier (and often double) springs can all potentially add to the issues a shooter may experience which could contribute to a less-than-ideal shooting experience, too.
Now, start using ammo that's at either the under or over-powered end of the normal range, and then consider a lighter, overall weight ... but with the same "dwell time" of felt recoil produced by the .45 ACP (more "push" than "snap") ... and things can become interesting, and maybe not in a preferable manner.
I've used my fair share of budget line 230gr ball loads that exhibited some varying felt recoil and muzzle blast signatures. While that may not be enough to create problems for an experienced .45 ACP shooter, a lesser experienced shooter ... especially using a smaller .45 with which they may have even less experience ... may find the added budget ammo factor just enough to potentially add to some shooting/functioning issues.
If some G36 owner told me that he/she was having some functioning issues with a G36 he/she hadn't shot in 4 years, and he/she only shot a larger 9mm normally, I'd probably test-fire and examine the G36 for myself ... and then focus on identifying and resolving whatever "shooter" issues may be involved.
Also, I tend to stick to using major brands of American made ammo in my own guns. I've used some foreign made 230gr ball loads in some .45's, and while I remember a couple of them running normally, I also remember a couple others offering some variable felt recoil & muzzle blast from within the same 50-rd boxes. The last time some of our SWAT guys came back from an outside school and complained of repeated feeding & functioning issues in some well-made 1911's, it had involved a budget ball load that wasn't made by one of the big American brands. A change of ammo resulted in normal feeding & functioning.
Oddly enough, at about the same time, I'd been told by another instructor at another agency of some similar functioning issues he'd been experiencing with his agency's G21's, using the same brand of imported budget ball ammo. Surprise ...
You can always find a Glock armorer to inspect your neglected G36. Might be even better if your range had an armorer in attendance, so he/she could test-fire your G36 for themselves, and then observe you shoot the G36.
Just my thoughts.