There's nothing automatic about the transfer of fuel to the supply tanks.
At start they're OFF, Prime pumps on for start (to prime engine feed lines), after start, Prime pumps OFF (as engine driven pumps are now sucking fuel from the supply tanks), and Transfer pumps ON. During flight according to the manual when a Aft pump or Fwd pump caution illuminates a specific action MUST be taken, which involves checking fuel contents, CBs and switch position, if it's obvious that lack of fuel over the pump is due to qty and aircraft attitude the pump should be switched off, then returned to the ON position when the attitude changes unless of course there's now no fuel. To be frank, it's a minor pain during flight but very predictable (normally).