Size between M and L

Hi everyone,
I need some help choosing the right size for the Canyon Endurace CF 7.
I was in Koblenz yesterday and got some advice there.
My height is 183 cm and my inseam is 87 cm — both measured on site at Canyon.
According to the size calculator (Picture), I’m still within the M range but right at the edge of L.
I test rode the Endurace CF 7 in size M and it felt good overall, but since I don’t have much experience, I can’t really say if it was truly the right fit.
The advisor on site told me that M would be a good choice. Even if I were closer to L, he said he would still always recommend the smaller size.
He initially set the saddle to the height suggested by the calculator, but then lowered it slightly.
This was my final saddle position. (2nd picture)
In all the excitement, I forgot to test ride the size L bike as well.
Now I’m feeling a bit unsure and would really appreciate your advice and expertise.

Thanks in advance!