XR500 - 5Ghz WiFi + Guest WiFi Anomalies

Before i start i will confirm i have factory reset the router and manually set my settings. I am also using the latest 2.3.2.40 firmware.

Basically i'm having this weird behaviour with the 5Ghz WiFi on my XR500. I only use the 5Ghz band and not the 2.4Ghz band so I can't say if this behaviour also happens on 2.4Ghz. I also have the Guest WiFi enabled on the 5Ghz band. One thing i've noticed is when connecting to one of the networks on my Galaxy S9 phone the other network (SSID) disappears from the wifi AP list on my phone and it takes 30 seconds-1 minute for it to reappear as an available network to connect to.

For example if i connect to my normal network SSID the Guest WiFi SSID will disappear and if i connect to the Guest WiFi the normal SSID for my network will then disappear. Both reappear eventually in the WiFi scan as an available network to connect to but not until after 30 seconds-1 minute later. 

I even had WiFi analyser open on my phone and could see the SSID disappearing when connecting to the other SSID.

Has anyone observed this behaviour at all on their XR500?

It's not an issue perse but more an inconvenience if i wanted to switch between networks i have to wait atleast a minute or so before my phone will detect the other SSID and allow me to connect to it.

I have a spare R7000P and have this exact same setup on it and i do not observe this behaviour. When my phone connects to one SSID the other SSID stays visible and i can connect to it immediately should i choose to do this.