I ran into this couple of weeks back. Reported the bug. Nothing I did allowed me to progress. Either find a save game beforehand or start over.

I don't use console commands, but iirc there is one which allows you to set that (or any other) task to "finished".
Ask the search function, a topic about that should be easy to find.

I’ve got a similar problem in that quest. I also killed the Alpha Infected and turned in the samples, but the next objective never appeared. The old marker doesn’t disappear, but you can’t interact with it either.

引用自 Rider：

We've recently found a possible cause of blocking storylines, and we're currently fixing it.

ty

引用自 Citizen Kane：

I don't use console commands, but iirc there is one which allows you to set that (or any other) task to "finished".
Ask the search function, a topic about that should be easy to find.

this didnt "fix it" but it allowed me to get past it

引用自 Rider：

We've recently found a possible cause of blocking storylines, and we're currently fixing it.

I gotta say, The dev response to issues and constant patches/updates is so refreshing to see.