that1cameraguy experienced a bug with his Tamron 28-75mm f/2.8 Di III RXD FE on the Sony a7III, which will hopefully be fixed in the very near future. He was trying to focus on a lightbulb and the lens was unable to obtain focus, so he tried adjusting a few settings, but the only thing that fixed the issue was powering the camera off/on. Not exactly a huge issue and it might only occur on the Sony a7III, so make sure to test your lens before relying on it for something like a wedding to make sure the same bug doesn’t occur with your camera.
To be clear that1cameraguy says he loves the Tamron 28-75mm f/2.8 Di III RXD FE, but he wanted to make photographers aware of this bug. This issue isn’t meant to dissuade anyone from purchasing the Tamron 28-75mm f/2.8 Di III RXD FE, because it is a minor issue that can be corrected via a firmware update later.
Tamron 28-75mm f/2.8 Di III RXD FE: B&H Photo / Amazon / Adorama
Sony a7III: B&H Photo / Amazon / Adorama