recording to https://issues.ibexa.co/browse/EZP-32157 there is an issue choosing the SA on a multi repository setup. If you have the same location ids in both repositories the siteaccesschoicer will display all possible siteaccess even if they are stored in the other repository. Website default, DB default,  SA site Website A1, DB A1, root location id for Website eg. 54, SA website_a1 Website B1, DB B1, root location id for Website eg. 54, SA website_b1 (just clone db a1)   There should be a limitation on the same repository too