I’m unable to set a staff of the viper as my hex weapon (for hex blade warlock) am I missing something? I’m attuned to it, proficient with it, and it doesn’t have the two handed property.

Do you mean Staff of the Python? While it can be used as an improvised Quarterstaff, it is not technically a weapon at all and therefore is not eligible to be a Hex Weapon. With DM permission, that could be changed by making a homebrewed version of the staff and change it from a “Staff” to a “Weapon” and choosing the Quarterstaff as the specific weapon, but that would be a houserule and not RAW.

I hope that helps.

I was speaking of the staff of the python (I always want to type viper for some reason).  So what you are saying is that none of the magical “staff of ...” are actually quarterstaves they can just be used as improvised quarterstaves? Cause if I add say the staff of striking it has the same issue and says in its description that it “can be wielded as a magic quarter staff...”.

Basically, yeah.

Go here and you can see that “Weapons” and “Staffs” are considered as separate categories: 

https://www.dndbeyond.com/magic-items

And Hex Warrior only works with “Weapons.”

Do some, like specifically the Staff of Striking make more sense as “Weapons” instead of “Staffs?” Perhapse. Can one easily make a homebrewed version of one that uses a Quarterstaff as its base item? Absolutely. But I would ask my DM for permission first if it was me since technically it would be a houserule.

If by default it isn’t a weapon then should it have the same options as a weapon (with the exception of setting it as my hex weapon) when you pull up the detail (customization) window or should it appear like a torch (which is also an item that you can attack with but doesn’t give all the weapon options in the customization area).  Sorry to be a bother I’m dealing with several new players and we are trying to figure out the differences between why a quarterstaff +3 would work in this situation and a staff of striking wouldn’t (I realize D&D Beyond has one classified as a weapon and one as a staff but since a staff can be a type of weapon is this an official “rules” thing or a classification decision within a coded program).

That is a fantastic question with a debated answer. Here is the latest debate I am aware of, you will have to come to your own conclusion:

https://www.dndbeyond.com/forums/dungeons-dragons-discussion/rules-game-mechanics/80938-q-staff-of-the-woodland-shillelagh

and here:

https://www.dndbeyond.com/forums/dungeons-dragons-discussion/rules-game-mechanics/24830-spellcasting-focus

So in the long run it comes down to a vague wording and a vague repeating of the wording when the official rule people were asked. They can all be used as quarterstaves but they aren’t actually quarterstaves. It’s pedantic like this that brought me to 5e from Pathfinder. 

Thank you for the time and effort you took to explain this.

No problemo. Happy to help.

It really all comes down to the DM’s ruling for stuff like this. For me personally, when I DM, if the staff in question seems to be specifically intended for use as a weapon then no problem.

Heck, for that matter, I allow most Rods to count as clubs or maces too. So say for example that you wanted to make a Rod of the Pact Keeper your Pact Weapon for Pact of the Blade I’d allow it. I know for a fact that the rules are completely unambiguous that it is not RAW whatsoever. I personally just don’t care either. It’s D&D, not the IRS. 😂😂

https://www.sageadvice.eu/can-you-use-a-staff-for-spells-and-abilities-that-require-a-weapon/
Game designer says it works fine, so there's really no need for debate unless you wanna take it up with him. Also, at no point does the book use the word "improvised" when talking about this.
"Unless a staff's description says otherwise, a staff can be used as a quarterstaff." -DMG