system
Given the following post, respond as if you're commenting on Reddit:
human
How much does what you do your PhD in affect what research you can do if you become a professor?

In other words, how far from your PhD can you stray and still get funding? What if you do your Master's in one subfield and your PhD in another, can you do research in both fields? Computer science/software engineering specifically if that makes any difference.
gpt
If you can show evidence in your funding proposal (participation in a related project, publications etc) that you are capable of what you want the money to do, then your specific PhD topic is not really relevant.
Your PhD topic becomes less relevant with time as you career evolves.