My solution

[LSkerkova]

Hallo, I had the same problem with 2000 miliseconds. Now I do not use get-uiatext and for long refreshing i changed sleep -Seconds 120, then refreshing is ok.

function WaitLoadDialog(){
$null = TestUnknownMessageDialog
while(TestLoadDialog){
#$null = TestUnknownMessageDialog
try{$text = $null
$text += $window | Get-UiaChildWindow | Read-UiaControlAutomationId}
#Get-UiaChildWindow | Get-UiaText -Timeout 150000 | Read-UiaControlName}
catch [Exception]{Write-Error $_.Exception.Message}
if ($text -match "error"){
Write-Error "Error. $text"
} else {
sleep -Seconds 120
"*" }}}

Then I had problem with saving, it worked only for first time. Now I save with press Ctrl+s

$null = $window.Keyboard.KeyPress([System.Windows.Forms.SendKeys]::SendWait("^{s}"))

#$null = $window.Keyboard.KeyPress([WindowsInput.Native.VirtualKeyCode]::LMENU)
#$null = $window.Keyboard.TypeText("FS")

It works but not ideally because the rectangle of the refresh window remains after end of script.
I will be grateful for your feedback.

Nice day Lidka