Lost account color in mail list

Hello

just upgraded to NC 25 and mail 2.0.3
Do I have an issue or we have lost the account-color to help identify which mailbox an email comes from:

image

When I search in the inspector, I do see a

<style nonce="">.mail-message-account-color[data-v-433b9883]{position:absolute;left:0px;width:2px;height:69px;z-index:1}[...]</style>

in the header, but I don’t see any usage in the page.

Can someone confirm ?
If that’s expected (as it is shown on the Nextcloud Hub 3 post), is there a way to restore it through Theming or an other hack ?

Best Regards
Mathias