I think we have a tendency to assume in this way:
If I experience headache, and to me and to majority of people that is pain, then if you arhat and buddha experience headache, you must also experience pain.
If someone cut my hand, and to me and to majority of people that is a great disaster, then if you arhat and buddha experience the same thing, you must also experience great disaster.
If all those things are called dukka or suffering, then to you arhat and buddha, that one will also called dukka and suffering.
We use what we experience and impose it to others, and think to my standard: If it is this to me, to you it is also this. If it is that to me, to you it is also that.
If we go to under the sun, you may feel very hot.
The degree of heat depends on the degree of your grasping to that heat. You can prove it yourself.
If you grasp it less, now the same heat become less painful.
If you can be totally free from grasping, that same heat is really not a pain at all.
So, where is the dukka? Where is the suffering?
Whether you call it dukka or you call it suffering, it doesn't matter. For people who can be absoluty free from grasping, that is not dukka, that is also not suffering.
Everything is a series of depending origination. If there is an "element" that can free us from grasping, and that is the realization of having no self, everything will turn to bliss. The heat of fire is felt as bliss, ice is felt as bliss, everything is felt as bliss.
Exactly same event, for us this is joy, this is suffering, for buddha everything is just bliss. Just because they have no grasping.
This is not something extraordinary. It just depends on how far we can be free from grasping, like when we are under the sun.
I am not here nor there.
I am not right nor wrong.
I do not exist neither non-exist.
I am not I nor non-I.
I am not in samsara nor nirvana.
To All Buddhas, I bow down for the teaching of emptiness. Thank You!