I have changed the time zone of my WordPress blog because I have relocated. After that, all times shown on the blog are wrong.

For example, my post was published at 2021-04-22 00:22 +0800 (Hong Kong Time). I have configured the time format on my blog to include the time zone. However I have relocated to the UK so that I changed the time zone of my blog to London. Now, the time is showing at 2021-04-22 00:22 +0100 which is obviously wrong.

How can I fix it such that it can show correctly as 2021-04-21 17:22 +0100?