Relevant telegraf.conf:

[[inputs.x509_cert]]
sources = ["https://my.server.com:443"] 

System info:

Windows Server 2019
Telegraf v1.19.0

Steps to reproduce:

1. Configure inputs.x509_cert
2. telegraf.exe --config "C:\Program Files\Telegraf\telegraf.conf" --test --input-filter x509_cert --debug

Expected behavior:

Certificate details returned

x509_cert,common_name=*.server.com,country=GB
x509_cert,common_name=Root Cert

Actual behavior:

No certificate details are returned
2021-06-16T16:52:07Z E! [inputs.x509_cert] could not find file: &{https:\my.server.com:443 false false }

Additional info:

Telegraf v1.18.1 on the same system does not show this issue.