Veyon master start is really slow

[Gaelds]

I use Veyon in my school and I need to use AD "computer groups" to display the right computer groups for each teacher. But every time I check "identify computer location via : Computer groups", it takes about 3mn to launch veyon master. Do you know the reason ?

I tried to used computer containers ou UO, but it doesn't work well for every room, I can't understand why it works for some UOs and not for others. I checked "Query nested user groups" option.

[Gaelds]

When i try to use "Computer containers or UOs", only a few UOs works as expected. Most of the time, "Parent UO" (from the veyon master computer) is displayed with every computers of children UOs :

"PEDAGO.lan/Ordinateurs/PC_EDS/CDI/CDI65" displays "PEDAGO.lan/Ordinateurs/PC_EDS/CDI/" computers
"PEDAGO.lan/Ordinateurs/PC_EDS/CDI/CDI65/CDI65-Eleves" displays "PEDAGO.lan/Ordinateurs/PC_EDS/CDI/" computers
"PEDAGO.lan/Ordinateurs/PC_EDS/CDF43/221" displays "PEDAGO.lan/Ordinateurs/PC_EDS/CDF43/" computers

It works well for some UO, for example :
"PEDAGO.lan/Ordinateurs/PC_EDS/CDF43/211"
"PEDAGO.lan/Ordinateurs/PC_EDS/CDF43/212"
"PEDAGO.lan/Ordinateurs/PC_EDS/NDBN-BAT-E/E201"

Also, I don't understand why I can't filter computer groups with "(objectClass=organisationUnit)" ??