Forgive me, looks like this has been the case since at least early this year per Plugin: Note Link System - Plugins - Joplin Forum. I would like it to be fixed, but it the plugin hasn’t been updated in years. I also mostly stick to the Markdown editor view anyhow.
As far as I know, links can’t be opened within Joplin, let alone within tabs within Joplin. I don’t know how much either feature is aligned with the spirit of Joplin.
While I see the benefit of in-app tabs opening web pages, I can do without them. If I need to open links on desktop, I typically have a browser window or two already open. As for mobile, opening a link in a browser or using my device’s app switcher works fine enough for me.
In case you currently require these features, consider using Obsidian with a compatible third-party web clipper like https://github.com/deathau/markdownload#obsidian-integration or https://github.com/DominikPieper/obsidian-ReadItLater instead. You could also consider (donating toward) development of either or both features.