How to set up teamwork in git?

Question

git

The situation - there is some part of the team - let it be 2 people for example - let's call them Developer 1 and Developer 2 - work in the project simultaneously with the same files, but the tasks are different. Both are on the frontend, but one can have many small tasks, the other has one big one, or whatever, as these tasks will be set in accordance with the tickets.
There is a master branch and a dev branch. Developer 1 maintains its own branch - let it be called dev-1, Developer 2, respectively, maintains the dev-2 branch. Versions for dev branches are all mandatory with alpha suffixes. When a version is rolled out for testing, it gets a beta version, and the branch of this developer is merged into the dev branch, the ticket gets UAT status, and the changes are applied on the developer server.
Once the testers have tested and changed the status of the ticket to UAT-Done, the changes should go into production as soon as possible. Those. the dev branch is merged with master, a stable version is assigned, without beta, and goes to production.
In this scheme - as I said, the tasks are too different, and developers do not have to and do not wait for one another to merge branches, and this constantly leads to conflict situations, both in terms of the git and the team.
The fact is that they just started working like this, before that everything was in the master, beta and alpha were never uploaded to the production anyway.
Who is experienced and went through these problems, how did you decide, how are you working now?