Sony A-Mount LA-EA4 Weirdness

[Brownie]

I bought an LA-EA4 for my A7RIII a few months ago. I noticed there was a problem with the 35-105, it would only connect with the camera intermittently. I figured I'd check into it later, then the holidays came, etc. It works fine with the 28-135 and 100-400, which is mostly how I use it. The other day I tried it with a prime, and it doesn't see the lens at all. No AF, no aperture.

Tonight I checked all of my A-Mount lenses. See below. They all work with the M4 and EA5. On the RIII and EA4, some work, some don't, some are intermittent. I can get the 35-105 to work sometimes if I clean the contacts on the adapter, then it stops. I think there's something loose inside the adapter. The 'intermittent' are depending on where the lens is at in the zoom range. Most work at both ends, the 70-210 works at both ends and in the middle. According to Sony all of them have identical compatibility and all are compatible on the LA-EA4/A7RIII combination.

I might think there was something loose in the zooms, but they all work with the LA-EA5, and there are two primes that don't work. The common denominator is the adapter. Fortunately, it was purchased through KEH and there's still warranty left.

Sony A7RIII and LA-EA4
Lens	AF	Aperture	W/A7IV and LA-EA5	Sony Compatibility
50 Macro	No	No	X	X
50	X	X	X	X
85	No	No	X	X
28-135	X	X	X	X
100-400	X	X	X	X
100-200	X	X	X	X
70-210	Intermittent	Intermittent	X	X
35-105	Intermittent	Intermittent	X	X
75-300	Intermittent	Intermittent	X	X
500 Ref	No	X (fixed)	X	X
80-200 HS G	X	X	X	X