Stuck on some sites

[CyJimmy264]

  class Otc
      def conn
        @conn ||= Faraday.new(url: 'https://www.htx.com') do |builder|
          builder.adapter :async_http, timeout: 60
          builder.request :json
          builder.response :json
        end
      end

      def payment_systems_request
        @payment_systems_request ||=
          conn.get('/-/x/otc/v1/data/config-list', { type: 'currency,marketQuery,pay,allCountry,coin' }).body
      end
  end

[1] pry(main)> hb = Otc.new
[2] pry(main)> hb.send(:payment_systems_request)
Faraday::TimeoutError: execution expired (Faraday::TimeoutError)

But it is actually ok with other sites. Can not find out which side to dig from.
It's also ok with default adapter.

[ioquatix]

I tried running your example:

require "async/http/faraday"

class Otc
	def conn
		@conn ||= Faraday.new(url: 'https://www.htx.com') do |builder|
			builder.adapter :async_http, timeout: 60
			builder.request :json
			builder.response :json
		end
	end

	def payment_systems_request
		@payment_systems_request ||=
			conn.get('/-/x/otc/v1/data/config-list', { type: 'currency,marketQuery,pay,allCountry,coin' }).body
	end
end

pp Otc.new.payment_systems_request

And it worked okay:

> bundle exec ruby ./test.rb | head
{"success" => true,
 "code" => 200,
 "message" => "Success",
 "data" =>
  {"country" =>
    [{"countryId" => 183,
      "code" => 1,
      "name" => "United States of America",
      "currencyId" => 2,
      "currencyName" => "USD",

Can you run with CONSOLE_LEVEL=debug and capture log output when it hangs?