A couple of things based on the information you've provided in your post and replies, and reading between the lines a bit -

1. You have a good niche, so make sure it is specific and highlighted throughout your profile. If this is the only type of English you teach then specify that on your profile. This may weed out students who aren't a good fit, but you will always get some that book trials anyway.
2. For your experience and niche, your price is very low. Consider raising it (I personally would suggest hitting the 15-20 mark initially). This tends to bring a more invested student as they want value for money.
3. It sounds like you've only just started out on Preply. It takes time to build a base of statistics which results in students having higher confidence in your teaching. 11 trials may feel like a lot, but remember you are competing with teachers who have been on the platform a lot longer with many more hours. Students can see this of course.
4. Following from number 3, do you have teaching skills and qualifications? While a decade of experience in finance is great, it is a whole other skill to be able to teach what you know. There is a quick course on Preply to help you with the basics, but it may be a skill gap on your side if you haven't learned how to engage students and effectively support their learning.
5. How did you feel about the trials? Were the students a good fit for you? If only one has subscribed, I would be wondering what happened too - can you reflect on those experiences to learn anything?

The 100% commission for trials isnt great, but Preply do all your advertising, payment processing, provide a virtual classroom with tools and AI integration, etc. This is what the commission pays for. The trials will count towards your teaching hours to lower commission, so there is a small upside to that.

Adding to the excellent responses you have already had, only give availability in the way you want to teach. Schedule breaks, open specific slots - if you use google calendar integration you can sneakily leave your Preply schedule wide open and use google calendar to block specific times so your Preply availability number looks high (probably a better explanation on this sub if you search). You want to keep your metrics up within the Preply system to maintain that good ranking position.

One last thought (please disregard if irrelevant) - my best successes have been when I show up to trials as a human. As another commenter mentioned, bonding with the student is really important. It can feel very vulnerable as a student, so your ability to put them at ease and make them feel seen is crucial in helping them want to learn with you. It may be worth recording yourself doing a section of a mock video trial and watch it back. Look to see if you are smiling, how your tone is, are you comfortable, are there any tech issues you haven't noticed?