Each of these should be taken a look at before going into SQL side, not to mention re-configuring anything:
Always the question nr. 1, when a behavior differs since the last time: What could've changed at the servers since the last restart?
- Have e.g. Windows Updates been applied to the servers recently?
- If so, which?
- Does your ULSLogs record fails concerning WFs?
- If yes, what is found? To where it leads to?
- Are there errors/alerts at CA?
- If yes, are they new since the errors appeared?
- Each concerning the issue, and each recently appeared alert should be taken a look at
- Have you confirmed the time synchronization matches between the servers?
- For how to, see e.g. 1, 2
- Are there recent actions done for related services?
- To see when and by who actions might have been done/triggered, see this
- Do you have backups which you can restore to a temporary VM and explore the findings, or do comparison?
As you mentioned about a recent update, applying a CU should ring an alarm if that has been done between the last restarts. If the CU's installation wasn't finalized, it might cause some services or features not to work correctly (such as workflows). Also any other Windows Updates within the same time interval should be looked at in detail. Many things can be discovered, and it wouldn't be the first time an update causes unexpected issues which should be rollbacked and waited for further fixes.