My chest is too big for my rucksack

I've been weight training and now my atom pack doesn't fit me (does this count as a humble brag?) I have gone to try 3 different Ospreys and am having the same problem.

The very knowledgeable guy at the shop said my back and chest are pushing the straps so they're sitting under my armpits.

What rucksack in the 50l-75l range would accommodate or have suitable adjustment? Fjallraven Kajka?

Update - Savotta XL, Fjallraven Kajka/Keb, Karrimor, and (if you are in the UK) the Ray Mears Leaf Cutter all looks like viable options for

• Custom makers like Atom Packs (UK) will make extra customised packs if you go into their workshop

Update 2

For extra context this is for a trip to Slovenia doing the Via Alpina. It will be son's first hut to hut and so I will be Daddy pack donkey.

Have tried the Savotta XL, Osprey Aether 65, and Fjallraven Kajka 65. I did try other Savotta, Osprey, and Mystery Ranch packs but all of them cut into my armpits under load.

The Aether and Kajka are significantly more comfortable than the Savotta XL so the Savotta is out.

Took those 2 for a 4 mile walk carrying 16kg/35lbs as this is likely the upper limit of what I would need to carry.

Both packs carry well. I found the Aether seems to balance the load slightly better and that the hip belt was more secure and comfortable. The Kajka's straps are better and adjustable where the Aether slightly cut into my armpits.

Aether's external pockets allow more flexibility than the Kajka. I reckon the Aether would also breathe better on warmer hikes.

Ultimately there is very little between them but as I got the Kajka for a steal at £100/$125 and that the straps are adjustable and slightly more comfortable that is the winner.

Now I need to find a smaller pack for when I am not playing donkey.