Rapid Overrun and Underrun alternating

[HoustonGuyNW]

I have Vban Receptor on 2 Android Samsung J3 phones. I get over-run and under-run rapidly cycling errors back and forth. Even when sitting next to the router. Set to OPTIMAL or FAST both options do the same while beside the router. When I turn off wifi then reboot the phone it gets better for a while after restarting the wifi next to the router.

Are these phone known to have issues with VBan Receptor?
Does that indicate a more underlying issue with the network? (What type of problems cause that sort of issue?)

An iPhone 7 and an iPad iOS14 both work fine.

Thanks in advance.

[Vincent Burel]

we need to update Android version anyway.