columnSpan and breakpoints

I'm used to work with tailwind in various projects :
As far I can remember, when I set ie

w-full md:w-1/2

w-full md:w-1/2

w-full md:w-1/2

w-full md:w-1/2, it applies w-full on screens smaller than

md

md

md

md, and w-1/2 on screens from md and bigger...

I've made many tries with columnSpan on filament and there's something I can't understand :

if I set columns(2), it sets two columns for screens bigger than "sm", and 1 under sm.
to override the first (sm and xs) columns, I must set ie
```
'default' => 2
```
'default' => 2
```
'default' => 2
```
'default' => 2
and from this point, everything goes wrong : when I set
```
columnSpan(['default' => 1])
```
columnSpan(['default' => 1])
```
columnSpan(['default' => 1])
```
columnSpan(['default' => 1])
, I expect that field to take 1 column of space on EVERY screen size, but it seems to work only on sm screens, but not on higher ones !?

What have I missed ??

Edit : more than strange, this works as expected with section, but not with grid !