The compatibility issue will be remediated in Update 4 GA.
Hotfix is available for Veeam 9.5 Update 4 RTM, please contact Veeam Support for assistance.
Alternatively, you can switch to version v1_4 with the considerations below.
The following Cloud Connect functionality requires changing request's version from v1_3 to v1_4:
The following may require changing request's content:
<xs:element name="TenantType" type="CloudTenantType" minOccurs="0" maxOccurs="1"/>