Seeking advice: Supporting a junior developer

I have a junior developer who has been with us a while but has only recently joined my team.

He seems to be constantly hitting "weird" issues with his local setup like deadlocks on database tables and things that no-one else seems to experience.

I know our software isnt the easiest to get working on but I feel totally at a loss helping him..

I suppose I want to know if this is my failure, his, or both of ours? And how can I help him progress when we've spent a week just trying to get his local environment running?

Has anyone else experienced something similar?

Ps: he's a remote worker so sadly sitting with him and setting his laptop up is limited to Teams collaboration.