Size is wrong in the palette


Im’ using currently unity 2020.3 and I have some problems to make a map.I’ve followed 3 different tutorial showing the same stuff + looked to this page and others related.

Fun fact I don’t have the same menu than the tutorial online or when reading the unity manual even choosing the same version.

Still , the size of the cell in the tilepalette is way much bigger than the asset I use ,creating big gaps making impossible to make proper map.I’ve obviously tried many time.
Instead of a spritesheet I’ve imported individual assets with differents size ,all the parameters are in the second screenshot.the 4 assets I tried to use(for a test) have all the same parameter and for the tilepalette itself I’ve tried with default parameter and modified (with no changes).

Hopping you help me for this part who seems very easy when looking some tutorials …

I already tried this method and it is not working ,thats why its bithering me so much .The assets in the screenshot are not at the same size ,the greenblock is 48X48 and one on the house 144X144,the second house is bigger.I have multiple assets with different size.

Should I make a palette for each group of asset and by size?For example a palette with all 48X48 then all 96X96 etc.

I’m very confused because,even if the bigger assets is divided in chunk of 48X48 is fine to me but can’t manage to do that simple thing .