Default gateway not preferred after going down and coming up

[DJenner8]

I have a multi-WAN setup with failover and load balancing rules.  My default preferred WAN gateway seems to go down for a minute or two a couple of times per day.  The secondary WAN takes over.  When the preferred WAN comes back up, it sometimes is not used for quite a while.  The secondary (slower) WAN stays as the default route.  I do get a notification from the router that the preferred gateway is added to the preferred WAN group.

Is there something wrong with my setup?  Otherwise, it seems to be doing everything I expect.

Is there some way of having my router tweak the default gateway so the preferred, faster WAN returns to use?  Something like an automatic reset of the gateway every hour or so?

Thanks,
Dave

[Derelict]

Any states established on the secondary WAN will not be automatically killed when the primary WAN is returned to service.

Which one is actually the default gateway at any given time should be gleaned from Status > Gateways and Diagnostics > Routes.

[DJenner8]

So, one-half hour after my primary WAN went down and up, the primary WAN is still not really being used.  The secondary WAN is currently saturated by a download by someone on my local network, but when I start a speedtest from a computer that hasn't had any such connection for days, the secondary WAN is still used.  There is very little activity on the primary WAN.  I am losing 80% of my bandwidth as long as this persists.

How long should it take before the primary WAN is used again?

Should there be a firewall rule to return to the primary WAN, or something like that?

[Derelict]

Status > Gateways

Diagnostics > Routes