We have an on-prem Azure DevOps server (2020 update 1.2). All our builds use the "default" agent (v2.181.2) created when DevOps was installed. I'm aware that it is possible to download and install agents from here: https://github.com/microsoft/azure-pipelines-agent/releases, but what are the reasons for doing so? Are they merely to provide bug fixes and performance improvements, rather than (say) new build tasks or build task features (which I assume are part and parcel of DevOps itself, and have nothing to do with agents)?
One of the reasons I ask is that last year I tried installing a new agent (v2.210.1), and builds had been working fine. However we recently started seeing our builds taking a long time, and in the agent log found that the agent was repeatedly attempting to downgrade to v2.181.2. Why was this? Is something limiting which version we can use, e.g. the version of DevOps itself, or a particular task in the build definition? (The build did continue to work when I reconfigured it to use the default agent, v2.181.2, which is coincidentally what the newer agent was trying to downgrade to).
I assume I would get similar issues if I was to create an agent using the latest version (currently v3.227.2)? Like I say, curious to know why I would want to install a newer agent in the first place.
