What am I doing wrong, I recorded real acoustic drums, I found a bit I liked, I split the clip at start and end point, loops smoothly.....I deleted rest of drums I didn't want......but then when I try and turn it into a groove clip, it changes the timing? I know I could read and muck around for ever with this, but I'm too busy and impatient, could someone please just tell me a quick step by step method of doing this

Sometimes SONAR gets the number of beats wrong. Open the clip in the Loop Construction View and fix it.

next problem, ive created loop using loop construction, and turned into a groove clip, however the indentations/corners that show the start and beginning of the loops have disappeared ? why?