different notes appearance

why do I sometimes have different notes appearance?
For example 3 eighth notes together and the fourth notated separately? (see image 1) …
And the other is, I would like to have a note of 3 beats (half + dot), but sometimes I get half note + quarter note tied together (see image 2). how do I adjust them to my preference? …

thank you in advance

They’re covered by different options in Notation Option > Note Grouping. Set global rules there and use Force Duration to override locally, where necessary.

It would also help to know the time signature of the examples.

Yes sorry it’s 4/4 …
but i did it all and i also watched this video https://blog.dorico.com/2020/03/tip-force-the-duration-of-notes /, but it doesn’t work with what I do …

For the attachment named “ezgif-2-d76”… you also need to make sure that this Notation Option is set correctly:

For your attachment named “1.gif” what happens if you select the passage, right-click > Beaming > Reset Beaming?

OMG you are incredible … hahaha

many thanks again, Everything works perfectly !!!