I've used written notation on staff paper for 50+ years myself. Yes, I do understand how this is confusing to someone learning BIAB. But hang in there.

Here's the thing about your example: you never enter a note in measure 2.

Try this experiment: just use your mouse in the Editable Notation mode and start clicking notes, working from left to right. If you skip a few bars, notice how BIAB assumes you meant a whole note in the prior note. If you do not skip a few bars but instead click soon after a note that is already entered, notice how BIAB creates the new note but also creates the length of the preceding note to make sure it doesn't overlap onto the note you just entered. Specifically to the point at issue, if the note BIAB creates spans a bar, it automatically creates the tie.

And if you don't like whatever it did, you right-click on the note and adjust it manually in the dialog box where it shows the starting point and duration (and volume) of the note. Sometimes you may also wish to check the checkbox for Rest instead of Note, and enter a rest in a specific place (which may remove a tie if there had been one; this depends on whether the prior note spans over a bar line).

Assuming you are using a mouse and not a keyboard to play the notes, this system of note entry is far better than any other I've used in any other music software. And I've used a lot and been paid to do so.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.