As i said: it can't be a filter problem, because using no filtration doesn't show grade 2 as usual, but something around grade 0.5 (estimated).
Although they shouldn't in theory, i have seen dichroic filters fade after many years of heavy use. But the filters in my enlargers are ok so far, at least they were the last time i used them before moving to the new apartment...
But i got myself some Dektol and N113 today, so i will be able to tell of it's developer fault sometime this week.
You're right. No filter should give something around grade 1-1/2 to 2, depending on the light. When you make a regular print, does it look too low in contrast? Someone suggested that the light source may be too yellow. If your line voltage is low, that could happen. Most modern color heads have regulators, but not all. Also, the regulator can fail. Are your exposure times longer than you would expect?
The Kaiser has a regulated power supply, the lamp in the Kienzle is directly connected to mains voltage (which is uncommon with color heads but nice to have).
Normal prints also look too soft and only get "normal" contrast with a significant amount of magenta filtration. Exposure times are normal (as far as i can tell).
Paper and safelight are most likely not the cause. I did a safelight test with pre-flashed paper, which didn't show any fogging up to 16 minutes. The paper is fresh, and the problem applies to Fomatone FB as well as Adox MCP.