Open the fork step. How many of the branches are required/necessary? If you have two branches (as it seems from the screenshot), then set 2 as required branches. This means that both of the branches of the fork need to be completed before the workflow can complete. I believe this will solve your problem.
The above method can cause another problem though. If in some cases only of the events get triggered, then the workflow will not complete, since it will be waiting for the second branch to get completed, and this might never happen depending on your business process, right? There are multiple different ways to solve this, but let's check first the above mentioned easiest solution.
Kind regards,
Karri
PS. Do not use any dummy steps with ABAP statement WAIT FOR n SECONDS. This is in 99% (or let's say 100%) cases wrong. Use the different workflow step types to achieve different "waiting functionality" (wait for events, wait for conditions, etc.).