Cloudflare Custom Page Under Attack Mode

Hello why my under attack mode with Custom Page keeps refreshing the Browser Integrity Check for like 5 times and it will proceed to the site. I also checked the console it gives error 503

Error:
https://prnt.sc/uuxrmd

Hello why my under attack mode with Custom Page keeps refreshing the Browser Integrity Check for like 5 times and it will proceed to the site. I also checked the console it gives error 503

Error:
https://prnt.sc/uuxrmd