Adding same ability score to different affects on one action

[DaPenguin]

Okay so I may just be missing something important here regarding why this does not work but please enlighten me if this is the case.

The build is this, Custom Lineage (for magic initiate feat at level 1) into druid for Shillelagh and some other fun cantrip (probably thorn whip for Thorn whip and spirit guardian combo)
Level 1 Cleric Arcane Domain.
Picking up the Booming Blade cantrip.

Up to level 7 I am planning on doing Shillelagh and Booming blade for 1d8+wis+booming blade.

Level 8 is where I have a question about how this works. The feature in question is

Potent Spellcasting
Starting at 8th level, you add your Wisdom modifier to the damage you deal with any cleric cantrip.

Now the way as a player I would interpret this to work is as follows. Shillelagh is unaffected as it is not a cleric cantrip (as I got it from Magic Initiate) and even if it did grant this bonus I don't imagine I would get wisdom twice on the same cantrip. Booming blade, as it is a cleric cantrip because of the arcane domain, gets to add my wisdom damage to it. So at this level it becomes 1d8+5(wis shillelagh)+1d8+5(wis booming blade)+2d8 (on a move).

Now I also could see it apply to the second 2d8 as well as it is a separate instance based on what the one sorcerer ability specifically states it being to any one damage roll and this one simply says to the damage you deal with any cleric cantrip. I don't think it works this way.

Is there something I am missing regarding adding this wisdom based damage twice given that one instance is from the weapon attack and one is from the cantrip? I would not be surprised if there was a rule against it but I want to focus on RAW, including sage advice and other official rulings. I didn't find one that answered this specifically but I am also not the best at finding these things.

[JackPhoenix]

Nope, not missing anything, it works perfectly fine, as long as you get the second effect of BB to trigger.

[Chaos Jackal]

Even if shillelagh was a cleric cantrip, it doesn't deal any damage. All it does is change the way your stick works; the damage still comes from the stick. If the cantrip actually dealt the damage and was a cleric cantrip, you would be double dipping, yes; see Hex Warrior and Lifedrinker for another example of adding a stat to damage twice. But neither of the above conditions is true, and you'd need both, so no interaction between Potent Spellcasting and shillelagh.

But booming blade, or any other cantrip with more than one damage instance? There's nothing in Potent Spellcasting that stops it from working on more than one of these instances, so yeah, they add Wis more than once. You'd do the same with something like create bonfire, for example; you'd be adding your Wis to its damage every tick.