I noticed my the front fluid levelon my XTR (13+kmiles) has dropped over the last month. Thought sudden excessice pad wear

Finally gave it a check (also due for fluid change) & I noticed fluid all around the bleed screw and fluid drip traces around it.

I thought maybe the screw had come loose. NO problem.

I changed the fluid, made sure the bleed screw was torqued correctly and cleaned all traces of fluid in the area.

3 days later, I noticed the base of the screw has fluid around it (more of a wet look rather than dripping).

Q1: can I use some PTFE tape (plumbing tape) or LPG thread sealing compound to stop the leak?
Q2: should I replace the bleed screw? (I can't & hope not it had been removed, then re-fitted cross screwed!!). I had the front tyre replaced about two months ago.

Q3: new caliper? I really don't want to go that route because of cost.

thanks for any views and helpful advice