The 34 can be a bit harder to troubleshoot why one of it's five tuners are having a problem, and also be a bit more sensitive with problems on the coax from the -16, like open ports or unused coax being connected to splitters.
I have no clue why it would just be tuner 2 on the hr34, which affects only certain channels, like 304.
I unplugged the power to the swm (16) and plugged back in, and I'm my channels back.
Directv is coming out tomorrow to look at everything.
All my other boxes are working fine as well. 4 h25.
"I'm guessing" the 34 is on one leg/output of the -16 & the 25s are on the other.
You might try swapping outputs to see if the problem stays with the 34, or not.