Double backslashes in http monitors after HF6 update.

Hello all, we have unexpected bug after upgrade our ltm BIG-IP 11.6.0 to HF6 the proble is after update and reboot all http monitors for example: GET /frontservices HTTP/1.0\r\n\r\n became like: GET /frontservices HTTP/1.0\r\n\r\n then we did update our second sendby ltm to the same HF6 so the string became: GET /frontservices HTTP/1.0\\r\\n\\r\\n fosure after that almost all vips gone down because monitor down.

this is too strage why no one else didn't come with the same issue.