ExchangeOnline getting disconnected partway through Maester test run

[mattcave]

I've noticed some strange behaviour with EXO-related tests recently. Some tests will complete successfully (maybe they pass, maybe they fail), but then tests later in the run will get skipped with "Not connected to ExchangeOnline". We were definitely connected 3 seconds ago, but suddenly we're not... Confusing. We see the same behaviour across many tenants.

For context we use a AccessToken to connect to ExchangeOnline prior to inking Maester, in case that gives any pointers.

Does anyone have any thoughts on what might be going on here?

Example snippet from verbose logs below showing how one second we're connected to ExchangeOnline, the next we're not.

Running tests from '<snip>/cisa/exchange/Test-MtCisaSmtpAuthentication.Tests.ps1'
Describing CISA                                                                                                         
VERBOSE: Exchange Online: True                                                                                          
VERBOSE: TransportConfig not in cache, requesting.                                                                      
VERBOSE: Returning precomputed version info: 3.7.1                                                                      
VERBOSE: Requested HTTP/1.1 POST with 68-byte payload                                                                   
VERBOSE: Received HTTP/1.1 response of content type application/json of unknown size                                    
VERBOSE: Adding test result detail for CISA.MS.EXO.5.1: SMTP AUTH SHALL be disabled.                                    
VERBOSE: Result:                                                                                                        
Well done. Your tenant has [SMTP Authentication](https://admin.exchange.microsoft.com/#/settings) disabled.
  [+] CISA.MS.EXO.5.1: SMTP AUTH SHALL be disabled. 1.03s (1.02s|15ms)                                                  
                                                                                                                        
Running tests from '<snip>/cisa/exchange/Test-MtCisaSpfDirective.Tests.ps1'
Describing CISA                                                                                                         
VERBOSE: Exchange Online: True                                                                                          
VERBOSE: AcceptedDomain in cache.                                                                                       
VERBOSE: SPF record resolved, checking lookups                                                                          
VERBOSE: SPF Lookups records not in cache, querying                                                                     
<redacted>                                                                        
VERBOSE: Adding test result detail for CISA.MS.EXO.2.2: An SPF policy SHALL be published for each domain, designating only these addresses as approved senders.
VERBOSE: Result:                                                                                                        
Well done. Your tenant's domains have at least 1 directives with specific mechanism targets, review authorized senders for accuracy.

| Domain | Result | Reason | Directives |
| --- | --- | --- | --- |
<redacted>      

  [+] CISA.MS.EXO.2.2: An SPF policy SHALL be published for each domain, designating only these addresses as approved senders. 2.83s (2.81s|19ms)
                                                                                                                        
Running tests from '<snip>/cisa/exchange/Test-MtCisaSpfRestriction.Tests.ps1'
Describing CISA                                                                                                         
VERBOSE: Exchange Online: False                                                                                         
VERBOSE: Adding test result detail for CISA.MS.EXO.2.1: A list of approved IP addresses for sending mail SHALL be maintained.
VERBOSE: Result:                                                                                                        
Skipped. Not connected to Exchange Online. See [Connecting to Exchange Online](https://maester.dev/docs/connect-maester/#connect-to-azure-exchange-online-and-teams)
  [!] CISA.MS.EXO.2.1: A list of approved IP addresses for sending mail SHALL be maintained. is skipped, because Not connected to Exchange Online. See [Connecting to Exchange Online](https://maester.dev/docs/connect-maester/#connect-to-azure-exchange-online-and-teams) 153ms (135ms|18ms)