Outlook is sending from the wrong email address

I have a Microsoft 365 Personal account which I have attached a personalised email address to, and I have added the personalised email address account to Outlook. However, every time I send an email out, it sends from the outlook.com address and not my personalised address.

In order to send it from the correct address, I must click the From button and change it from the first mention of my personalised email address to the second mention of my  personalised email address. My personalised email address is listed twice,  as below:

I have to do this on every email though, since my outlook.com address (which is in fact the first mention of my personalised email address) is always the address chosen by default.

How can I make my personalised email address (i.e. the second mention of my personalised email address) the default send from address?