Bracketing not working as it should

[Billyq]

Hi I have a Sony A7iii, Im trying to get it to bracket more than 3 pictures and its not playing ball. I have seen a couple of posts (elsewhere I think) which mention this so wonder if its an issue and if it has been fixed maybe in a firmware update?

Ive tried silent shooting, this did give me one or two 5 shot bursts of bracketed images but now it has gone back to refusing to do more than 3 and sometimes only 2.

Am I missing something?

I want to use the camera for timelapses so often take an exposure that is completely over exposed for the first part of the shot and which comes into correct exposure when it gets dark. 

Is there a 3rd party intervalometer that can do continuous and via wired remote trigger?

Thanks for any help.

Billy