OUtlook 2021 subject line truncation

Hi,

One of my colleagues use Outlook 2016 for a long time, the subject of email messages so far are OK, recently, she change the new computer and using new version of Outlook (2021) and she found that the subject line is truncated when the email messages show on the preview pane, this scenario will not happen on Outlook 2016, appreciated that if someone can help, many thanks.

Please find below dump screen for your reference:

Outlook 2021

Outlook 2016