@Blade2946 

Hey

Assuming I use the same SSID on both the AP's on both 2.4 and 5 ghz on the AP's as it is on the internet router? 

For example if my internet router wifi SSID for both 2.4 and 5 ghz is test 123, the same exact SSID is copied to both the AP's?

You would need to manually configure the APs individually, however yes you could just "copy" the settings to have the same SSID and password / Security.. However ensure they are all on different channels

eg..  2.4ghz  1  6   11      5ghz   36  40  44

You wont however get seamless roaming, the clients will hold onto the current AP until the signal is gone.. then disconnect and reconnect to a stronger AP.   You could Mesh the EAPs but they liekly wouldnt mesh with the router so not much benefit.  Ideally the 2x 245s should be on a controller

The internet router wifi config is setup to combine both 2.4 and 5 ghz, and devices will auto connect to the most suitable range, not sure if this is band steering. 

I noticed this option is also available on the AP's.   

Yeah this is referred to as Band Steering on the EAPs, on the router is may be called SmartConnect.    Its designed to work as you say, move you to the 5 for speed or 2 for range depending on signal strength and support

When I do so and I leave the AP's on for about 5 minutes all wifi signal in the house is disabled. 

Since that is the case I believe some sort of conflict is taking place, assuming it is the SSID's? 

Not the SSIDs, that is literally just a name.  Likely they are on the same channel and disabling due to conflict of airspace. try changing channels and provide us more info if you can

I want to configure the AP's so that is is a single SSID just extending the current range. 

The other incorrect configuration I could have done, might be the fact that I entered the same primary and secondary dns config on each of the AP's as what is set on the internet router. 

I would just let the router handle DNS, no requirement to set it on the APs.