Decklink Duo2 resolution question

I am planing to build a simple multicamera setup using PTZ cameras with DECKLINK DUO2 and VMIX, I have seen some reviews mentioning that although Decklink Duo2 have an option for 1080p50/60 and 1080i50/60 But cannot be activated and that only 1080p30 can be used.
I just want to confirm this before investing, and please guide me for good 4 sdi input capture card.

They are wrong, I have multiple PCs running vMix with Duo 2 cards working in 1080p60.

Thanks ... maybe its their PTZ Camera fault or settings I have never used this setup before

There are a lot of cheap PTZ cameras that use cheaper chipsets designed for security cameras that generate signals that are not SMPTE 424M compliant. BMD cards need real 3G-SDI signals.