Thanks for your quick reaction.
I can confirm that for both solutions, the lcr module works well: * Ubuntu 18.04 package 5.4.5 with Integer avp names replaced ('i:' => 's:') (https://github.com/kamailio/kamailio/issues/2709#issuecomment-820930217) * Compiled from latest git branch 5.4 (https://github.com/kamailio/kamailio/issues/2709#issuecomment-820996666) with default avp names (i:709, i:500, i:712)
Since I don't want to use the git version in production, I would be grateful for a quick official 5.4.6 release.
Also, I assume this problem may affect most of kamailio 5.4.5 deployments using lcr because the Integer avp names are suggested by the official documentation (https://www.kamailio.org/docs/modules/stable/modules/lcr.html).