I have recently purchased a BV6000s and find that I cannot use both SIM accounts at the same time.
Only the SIM designated as "Preferred SIM for Cellular data" is functional. The other SIM, while recognized, will not send or receive calls or SMS messages.
Is this a design flaw of the BV6000s or do I need to return this particular phone for repair or exchange?

Did you check the another SIM card can work in the other phone?

sonoffar wrote:

I have recently purchased a BV6000s and find that I cannot use both SIM accounts at the same time.
Only the SIM designated as "Preferred SIM for Cellular data" is functional. The other SIM, while recognized, will not send or receive calls or SMS messages.
Is this a design flaw of the BV6000s or do I need to return this particular phone for repair or exchange?

this is how most phones are designed to work as youd be getting two signals on the same device which may get mixed up so you select the preferred sim. to get around this you could forward any text and calls to the sim that you have selected.