Hi Oliver,
I had a longer conversation with Mikrotik support. They bought a bunch of Intel SFP modules:
We ordered a bunch of them for us to fix this compatibility issue. We are not sure if we are going to be able to fix this so soon since we added compatibility to a different module and it seems that it broke compatibility with these modules. We will try to fix this compatibility in the future, this will take a while for us.
So, it will fixed in the future, but the timerange is unknown.
cu denny
Just to add some fuel to the dumpster fire - Intel SFP+ modules (here E10GSFPSR ) work perfectly well when coupled with non-Intel SFP+ receivers. My examples are Mellanox Connect-X 3's (working), Intel x520-sr1 (nope) and a Cisco switch (working) with an appropriate command.
use DAC cable, i preferred 10GTek or amphenol, works most of the time both in server side and mikrotik side
My recent experience here says it doesn't matter. DAC works with Mellanox, SFP+ works with Mellanox. Both fail with Intel cards.