How long to try an offer before pivoting?

I am a coach. I have a large list (about 7,000). I started out as a designer building my list and then part way into list building started offering coaching to fellow creatives. For the past 6 months or so my general offers (for 1:1 coaching) to help them create more success aren’t converting into consults. I’m prepared to get more specific in my offer so that I can add targeted value. I’m wondering, how long should I try an offer to my people before switching? As I’m writing this, I’m realizing that I’m assuming my first one obviously won’t work otherwise I wouldn’t even be considering this question…haha. But really. If it doesn’t land with my list after a few tries should I just keep pivoting until I get one that sees a response?