Is there a limitation in setting up the supplier contact's username under user account setup?

Summary:

We are experiencing an issue with a specific supplier who does not receive notifications through the notification bell, although the notifications appear in the BPM worklist. We have tried various solutions without success. As a last resort, we changed the supplier's username by removing the space and replacing it with a period ("."). After making this change, notifications started coming through the notification bell.

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24C

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