The change in
WT-5150 is enabling the LAS sweep to clean the obsolete records as that is required for the relevant_history project, but it re-introduced a data inconsistency bug. When running 10 parallel test/checkpoint processes with the configuration from WT-4750.
The fix in
WT-5150 is no reason for the failure, but it was hiding the data mismatch bug. Earlier there is no LAS sweep that was happening, so the issue does not occur.
The data mismatch bug needs to find and correct it.