Did you set the InvalidCertificateAction to Ignore with the Set-PowerCLIConfiguration cmdlet?
Did you check that TLS v1.1 and v1.2 are enabled on your station?
Check with
[enum]::GetNames([Net.SecurityProtocolType])
And eventually, change it with
[System.Net.ServicePointManager]::SecurityProtocol =[System.Net.SecurityProtocolType]'Ssl3,Tls,Tls11,Tls12'