When overriding the new tab page with an extension...

[jls28]

When overriding the new tab page with an extension
(using chrome_url_overrides/newtab, this excellent extension: https://github.com/snw-mint/fluent-new-tab):

Each time webview2 starts and the new tab page is opened for the first time (edge://newtab),
the initial load takes more than 10 seconds—even on a fast machine.
In practice, this delay makes the extension almost unusable.
Of course Microsoft Edge does not suffer from this issue.

Note : after the NavigationStarting event and before the SourceChanged event,
this slow loading generate this message to debug output :

runtime 141.latest:
[548] [0219/124141.012:WARNING:third_party\crashpad\crashpad\edge_watson_uploader\win\device_ticket.cc:151] Timed out waiting for device ticket. Canceling async operation.
[548] [0219/124141.012:ERROR:third_party\crashpad\crashpad\edge_watson_uploader\win\device_ticket.cc:187] The identity is null.

runtimes 142.lastest, 143.latest, :
[10496] [0219/125320.229:WARNING:third_party\crashpad\crashpad\edge_watson_uploader\win\device_ticket.cc:151] Timed out waiting for device ticket. Canceling async operation.
[10496] [0219/125320.229:ERROR:third_party\crashpad\crashpad\edge_watson_uploader\win\device_ticket.cc:187] The identity is null.
[10496] [0219/125320.299:ERROR:third_party\crashpad\crashpad\util\net\http_transport_win.cc:315] WinHttpSendRequest: Impossible d’établir une connexion avec le serveur (0x2efd)

runtime 144.latest:
[11108] [0219/125743.382:ERROR:third_party\crashpad\crashpad\edge_watson_uploader\win\device_ticket.cc:187] The identity is null.
[11108] [0219/125743.382:ERROR:third_party\crashpad\crashpad\edge_watson_uploader\win\device_ticket.cc:187] The identity is null.
[11108] [0219/125743.415:ERROR:third_party\crashpad\crashpad\util\net\http_transport_win.cc:315] WinHttpSendRequest: Impossible d’établir une connexion avec le serveur (0x2efd)

Also even without extension, the same problem exist when opening the page "edge://newtab" with inPrivate mode, it display an usefull internal page but after the same delay and the same error message to the debug output;

[jls28]

Fixed in version 151, this issue is likely a regression—versions 138 and 139 were unaffected.