[SR-Users] Empty Subnets in Permissions Module

Greetings all! I have two deployments of Kamailio: one running version 5.3 and one 5.5 with practically identical configurations, same (MySQL and REDIS) data sources. We have customers that we assign an ACL "group" to, where the ID of this group resolves to records in the "address" table in our MySQL database - using the "grp" field. On the box running Kamailio 5.5, we have noticed that if a group has ip_addr=0.0.0.0, mask=0, port=0 - and we try to run the allow_source_address() - it will return false, thus failing this phase of the authentication process. However, on Kamailio 5.3 we are not seeing this issue, i.e. if a customer is assigned a group where the ACL is 0.0.0.0/0 - it will let him through. Has something changed that I'm not aware of? Any suggestions on how to resolve this? My best, Tom