Hi. I'm a long-term Sony A99 shooter with several A-mount lenses inc. Sony Zeiss 24-70 f/2.8 SSM and Tamron 70-200 f/2.8 USD. 

I recently bought the A7II, along with both the LA-EA3 and LA-EA4 adapters. The LA-EA4 works perfectly - almost identical to my A99, so I'm very happy with that. But when using the LA-EA3 with AF System set to Phase Detect, I find the AF to be very slow and sometimes unable to lock focus, unless I'm in very good light and with plenty of detail in the target. 

Has anyone else had this experience, and is it normal? I'm currently considering returning the LA-EA3 to the supplier for a refund.

Oh, the A7II is running firmware v3.10, as supplied.

Thanks in advance