Cyclone V and data conversion board - arbitrary frequency

Hello Altera Forums,

I'm using a Cyclone V GX Starter Kit with a data conversion board plugged into the HSMC slot.

I am using a 50MHz clock generated by a PLL. This clock is sent to pins 95 and 155 of the HSMC (for ADC channels A and B ). On the DCB card, I have pins 1 and 3 connected on J3 and J7, as per the manual.

I am able to record data with this with no issues (Signaltap_50MHz.png):

https://alteraforum.com/forum/attachment.php?attachmentid=14861&stc=1

When I change to PLL clock to some other frequency however, the data I get is nonsense (example is at 40MHz, but the same issue occurs at other frequencies. I've tried 60, 100, and 150MHz) (Signaltap_40MHz.png):

https://alteraforum.com/forum/attachment.php?attachmentid=14862&stc=1

Is there anything I should be checking to make this work properly? I have read the manual for the DCB, and found no indication that it can't run at an arbitrary frequency.

If there's any more info I can send to help solve this, please let me know.

Thank you for your assistance,

-Sam