Flexmatch - Filling a session to full in backfill whilst in Standalone mode

Hi,

The documentation for backfill implies that it is useful for starting sessions with less than idea number of players and then ramping up to more players as the session goes on. It's unclear how this is accomplished when using Flexmatch in Standalone mode at the moment.

Suppose a situation where I have three tickets in the pool. The ruleset specifies that a match's team (for the sake of argument we'll say there is only one team here) can have between five and ten players.

Ticket A has 3 players. Tickets B and C have 2 players.

The expected outcome is that A, B and C can all fit into a match. Given the ruleset, it's not unexpected that only A and B make it in on the regular matchmaking process, leaving C out.

If I submit this match back into the pool as a backfill, my expectation is that C then makes it in, as that would put the match count to 7, which is within the range.

However, what I've observed in test is that C never gets in. It seems like, because the session is valid (5-10 players, five are in), Flexmatch never considers adding C to it.

I'm wondering if this is a limitation of Flexmatch in Standalone mode?

Thanks,

Hannah