Cannot get na.locf to work

Your question is rather simple but you have made it complicated by including unnecessary details.
Have you read what a reprex is? If not please read here FAQ: What's a reproducible example (`reprex`) and how do I create one?
It will help you ask questions in a way that peoiple can instantly help you.
For your current question the two major improvements should be:

  1. Use code formatting.
  2. Reduce the problem to a minimim (use a toy data instead of all columns of your real data)

Best wishes