Wages
You are paid below market wages. There is nothing wrong if this happens temporarily. A company may have a crisis that has caused them to cut salaries in order to save jobs. If you can see that in the long run, your salary will return to market level, it's okay to be a little patient. After all, you work in a team and it makes sense to work your way out of the crisis for the sake of the team.
However, there are times when you are doing a great job, time goes by, but your salary does not increase. You see that other companies are ready to offer financial conditions that will be much better. In this case, first of all you need to talk to the manager. Because if you keep silent, the supervisor will think that you are satisfied with everything. Sometimes such a conversation is enough for the manager to collect data, analyse and increase the salary. If you are not satisfied, finish your current job, find a replacement and go to another company. Leave in a good way so that you still have the opportunity to come back. Maybe things will change in the future, the company will increase salaries, and you will want to work there again because you enjoyed it.