HTTPS Virtual Server doesn't automatically direct existing connections to available pool member

"When a pool member fails to respond to a health monitor, the system marks that pool member down. Persistence entries associated with the pool member are removed when a new connection matches the entry or when the timeout period is reached. If a new connection matches a persistence record that has not timed out, the BIG-IP system removes the old persistence record and creates a new entry." (K15095: Overview of the Action On Service Down feature).

So a current or a persistent connection will still be forwarded to the failed server until the connection times out or is killed.

With a OneConnect profile, the load balance decision is made based on each HTTP request, not just at the beginning of a TCP connection, as I understand it.

It is probably better to get other issues (SSL) out of the way before testing this issue.