Receiving text messages twice with Samsung A7 Dual SIM

I recently purchased a dual SIM Samsung A7. One issue one have been having is that I am receiving all text messages twice.

This issue persists across messaging apps (I have tried the Samsung and Google versions). In the Samsung app, I can see that one of the texts comes in generic, and the second one -- with a small icon indicating SIM card #1 .

I haven't been able to find a setting that allows me to disable this... feature, I guess? Any input would be appreciated.