Scraping slow down

Web Scraper version: .3.8
Chrome version: 70.0.3538.77
OS: Windows 7

Sitemap:

{"_id":"cmentarze","startUrl":["http://polskiegroby.pl/s/szukaj.php"],"selectors":[{"id":"land","type":"SelectorLink","parentSelectors":["_root"],"selector":"h6.bd-textblock-52 a","multiple":true,"delay":0},{"id":"miejsce","type":"SelectorLink","parentSelectors":["land"],"selector":"h6.bd-textblock-67 a","multiple":true,"delay":0},{"id":"cmentarz","type":"SelectorLink","parentSelectors":["miejsce"],"selector":"h6.bd-textblock-83 a","multiple":true,"delay":0},{"id":"opis","type":"SelectorText","parentSelectors":["cmentarz"],"selector":"p.bd-textblock-11","multiple":false,"regex":"","delay":0},{"id":"adres","type":"SelectorText","parentSelectors":["cmentarz"],"selector":"p.bd-textblock-18","multiple":false,"regex":"","delay":0},{"id":"kontakt","type":"SelectorText","parentSelectors":["cmentarz"],"selector":"p.bd-textblock-20","multiple":false,"regex":"","delay":0}]}

Error Message:

After a while of scraping the process slow down very much, in console log there are:
{"error":"tab load event timeout","timestamp":1541549262,"level_name":"NOTICE","message":"request timed out. continuing"}
background_script.js:1 {"timestamp":1541549262,"level_name":"INFO","message":"will not be sleeping for additional time"}
background_script.js:1 {"timestamp":1541549262,"level_name":"PROFILE","message":"9 DataExtractor getData"}
background_script.js:1 {"timestamp":1541549262,"level_name":"PROFILE","message":"60042 ms job execution"}
background_script.js:1 {"url":"http://polskiegroby.pl/s/szukaj.php?miejsceok=496&landok=4","timestamp":1541549262,"level_name":"INFO","message":"Job execution started"}

Meanwhile when I open the page in another Chrome window it opens normally. How to fix this?

To access error messages follow these steps:

  1. Open chrome://extensions/ or go to manage extensions
  2. Enable “developer mode” at the top right
  3. Open Web Scrapers “background page”
  4. A new popup window should appear.
  5. Go to “Console” tab. You should see Web Scraper log messages and errors there.
{"url":"https://www.superhentais.com/hentai-manga/namanaka/5374558","timestamp":1550186877,"level_name":"INFO","message":"Job execution started"}
background_script.js:1 {"error":"tab load event timeout","timestamp":1550186937,"level_name":"NOTICE","message":"request timed out. continuing"}
background_script.js:1 {"timestamp":1550186937,"level_name":"INFO","message":"will not be sleeping for additional time"}
background_script.js:1 {"timestamp":1550186937,"level_name":"PROFILE","message":"43 DataExtractor getData"}
background_script.js:1 {"timestamp":1550186937,"level_name":"PROFILE","message":"60079 ms job execution"}

Im having the seame problem,the scraper slows down after some time.