Zero-Cross detector problem
Resistor
A 150kΩ resistor on 220Vac is dissipating 0.32W and probably should be burning up.
A 330kΩ resistor on 220Vac is dissipating 0.147W, which is in the rated range.
As one of the commenters suggested, your math of 10x higher is a bit off. Maybe you should try a 330kΩ resistor?
Interrupts
Don't tell us the interrupt durations, show us the scope capture of the node on pin 5. If the scope capture checks out, then you know it is a firmware problem and you are describing a hardware problem. Please ensure that you have a hardware problem before describing it in terms of software.
Just speculating without a scope capture, but it could be that your pull-up is too strong? You have a lower resistance than the other. Maybe try a 10k? 20k? Again, post a scope capture.