As others said, comments are the rarest of engagement. You can't force them. Most are silent readers and many do not feel comfortable commenting. Even for the biggest creators, that is just how it is.
Tip: Ask a question in your author's notes to prompt some answers.
If what you're looking for is someone to tell you what they liked and didn't like, you won't get much of that in comments. Usually, comments are emojis, acronyms like "LOL" or just a few words. Even rarer are the loyal readers who theorize (I love those). What you seem to be looking for is a beta reader?
You should also look at your subscriber list. If most "readers" are just sub4sub, aka other creators, such tactics dont really bring genuine engagement, just a quick boost at the time you made a pact with them to sub and stuff. What you want to aim for are actual readers who will eagerly await the next chapter release and engage.