Downgrade 9.1 to 8.6 - 8.6 settings not avalable in Wyse Management Suite

We notice, if we dowgrade a device firwmare 9.1 to 8.6 the specific 9.1 device settings still exist. We cannot acces to the 8.6 settings. Like you se above This is wdm url for a device not update to 9.1 https://wmsserver.symta.fr/ccm-web/admin/device/36 https://wmsserver.symta.fr/ccm-web/admin/group/8/device/36?deviceType=6 And this is wdm url for a device downgrade after update to 9.1 https://wmsserver.symta.fr/ccm-web/admin/wms20/configuration/device/64 https://wmsserver.symta.fr/ccm-web/admin/wms20/configuration/deviceException/64?deviceType=6 Thanks for your help.