How do you open messages you want to read? By simple L-click on a message in the message pane or by double-click in a new tab or a new window?

this is happening on a android phone

Sorry, I can't test this since Thunderbird Mobile is not yet available for iOS. You should have mentioned that your issue concerns Thunderbird Mobile and not the desktop version

I have moved your question to the android section.

i don't know how my question ended in iphone section

What version of the app are you using?

I've been unsuccessfull replicating your issue report on v16.1 and beta 17.0b2. On both versions I opened and deleted a couple of messages. The next message was correctly displayed after the deletion with no switch back to the message list. I opened emails from the account and unified inbox's.

Settings > general settings > interaction: - After deleting or moving a message [show next message]

i am using a motorola stylus 5g 2024 with android 15, using thunderbird 16.1, having messages on top read or unread and i delete a message on top of the message using the trash icon, it goes to the message list not the next message

i have this set Settings > general settings > interaction: - After deleting or moving a message [show next message]