When you have a Grid with data and you filter on one of the values, that goes for more than one page, and you navigate to the next page, if you on the second page, try to filter for a value that has only one page, you get no results. If you move back to page 1, and then filters again, everything is back to normal.
Is this by design or a bug?
Definitely a bug. We’ve made improvements to the new UDTable (replacement for UDGrid) in v3 that will resolve this issue.
Also spotted an issue when using -serversideprocessing it breaks pagination (numbered pages still show, but clicking them, while the number changes to indicate it’s been clicked, the data remains the same as if i were on the same page. as soon as -serversideprocessing is removed it functions correctly again).
Is this a serversideprocessing grid ?
Yeah, unless my understanding is wrong.
I basically have a ud grid, inside the endpoint i use the IIS app pool identity account to run an invoke-sqlcmd2 to pull data into a variable, run a for loop on that, and for each object, i transform the data with a few extra bits (a ud button in one of the rows which launches a modal) and so on.
I did notice that in the ud documentation for -serversideprocessing it says ‘This disables client-side filtering, sort and paging.’ Maybe it’s my understanding or usage that is just wrong in this case 
You need to read the doc about using server side processing to make sure you establish the server side scripting needed for it to work 
New-UDGrid -Id ‘Grid’ -ServerSideProcessing -PageSize $CustomPageSizeInt -Title “serversideProcessing”
-Properties $Properties -Headers $Headers -Endpoint {
if ($Skip -ge $DATA.count) { $Skip = $Skip - $Take; if($Skip -lt 0) {$Skip = 0} }
$DATA |
Sort-Object $SortColumn -Descending:(!$SortAscending) |
Select-Object -Skip $Skip -First $Take |
Select-Object $Properties |
Out-UDGridData -TotalItems $DATA.count
}
but my question were to @TmJr75
but the above solve the serverside issue with the pagenation and filter 
No, just a normal grid, no serverside processing here.