Hint: it's easier to get free beta readers if you're enjoyable to work with and don't start using them as writing teachers o'r asking them really similar questions over and over.
Beta readers are there to give you feedback on how they feel about the plot, characters, tone, prose, any continuity errors or grammatical errors they found, and occasionally offer ideas to correct things. They are not there to give you the answer.
If a beta reader says "the scene is dragging and I don't get invested in the characters" it's your job as the writer to analyse your work and find out why that could be and then fix it. I think that's why a lot of people get frustrated with you on the forums, you get an answer and say you understand the answer, and then the next day you ask a question that demonstrates that you didn't understand the answer and also didn't try and work it out really.
The frustration you get on the forums is going to be the same frustration you'll get from any beta reader, free or paid.
I'd advise before getting a beta reader to at least finish writing the script for your entire story (or arc if it's written to be a neverending story) and doing at least 1 pass for edits on your own before hiring a beta reader. Beta readers are the final step before the final product, which means you need to have something as close to the final product as possible.