Repetition due to expired tasks

We've been struggling for some weeks with duplicates being shown to annotators in multi-user session when carrying out image annotation. It has led to some significant amounts of re-work / annotation due to the same examples being presented repeatedly.

Prodigy version: 1.11.8a4 (installed to try and resolve dupe issues we saw from another thread)
Our config includes:
"feed_overlap": false,
"force_stream_order": false,

We've now noticed in the log, messages similar to the following:
FEED: re-adding 9 expired tasks to session

What we think is happening is that complex image annotation is taking some time and with a batch size of 10, the server is expiring a batch and then re-adding it to another annotator.

Obviously we can reduce the batch size but the problem is that we'd ideally like to keep the history at 10 so people can go back if needed (understand it's the min of batch size and history size).

Are we able to control the expiry time that the server waits for before it expires and re-allocates batches?