Hello mneirynck,
in Prometheus metrics when there is no # TYPE metadata it defaults to UNKNOWN metric type. This is suitable for xHTTP_PROM because it blindly takes Kamailio registered counters and export them. We do not know if they are Prometheus counters or if they are Prometheus gauges.
Currently OpenMetrics recommend not to use UNKNOWN metric types https://github.com/OpenObservability/OpenMetrics/blob/main/specification/Ope... and Cloudwatch do not support unknown Prometheus metrics https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/ContainerInsi...
On the other hand kamailio_exporter exports a set of metrics and defines clearly if they are counters, gauges, etc. So at this moment I recommend you to use kamailio_exporter to interface with Cloudwatch https://github.com/florentchauveau/kamailio_exporter/blob/master/collector.g...