Don't understand weapon swap

[marco]

I cannot use my weapon II because if I swap to it and use it, it automatically reverts to weapon I. Does this have to do with the main attack being bound to weapon I? And if yes, do I need to find a weapon for slot II that matches the skill? Then what's even the use of weapon swap?

[Hefutoxin]

You can choose specific skills to use with each weapon.
The extra skill points you get from those books can also be split between each weapon slot.

Either you are using a skill specific to the weapon or you have set it so a skill is only used with weapon slot 1.

[TheOne320]

https://maxroll.gg/poe2/resources/weapon-swap-mechanics