It looks like mongodb_exporter returns a wrong version number.

The following is from a PMM 2.44 environment.

$ pmm-admin status
Agent ID : /agent_id/aa85e32f-49ea-43b2-9690-71aa8c6047a4
Node ID : /node_id/da4aed1e-a0c0-44c7-9824-9b9487d32586
Node name: corradotest-mongodb-mongos00.c.consultants-206215.internal

PMM Server:
URL : https://10.128.0.9:443/
Version: 2.44.0

PMM Client:
Connected : true
Time drift : 22.011µs
Latency : 471.946µs
Connection uptime: 100
pmm-admin version: 2.44.0
pmm-agent version: 2.44.0
Agents:
/agent_id/2f019725-9b13-4b43-95c1-7d743a92e27e node_exporter Running 42000
/agent_id/60a7318c-79b9-4de4-9650-3f3fc05c0de2 mongodb_exporter Running 42001
/agent_id/80f95cfa-a934-475d-8694-5ad07824941e mongodb_profiler_agent Running 0
/agent_id/c0f3d758-72c4-4131-8578-52c8c806aedf vmagent Running 42002

$ cd /usr/local/percona/pmm2/exporters/
$ ./mongodb_exporter --version
mongodb_exporter - MongoDB Prometheus exporter
Version: v0.39.0
Commit: 2b2cccca21104c2a00cb53bd0d785b3d656fe803
Build date: 2024-12-11T12:44:45+0000

The build code 2b2cccc is the one for version 0.43.1, but instead it returns 0.39.0