Does BLtouch/level bed work or am I doing something wrong?

I have a gmax 1.5+ running 1.1.8 marlin code.

We have a heated bed with the Build tak surface on it.

I typically run the bed at 48C and my hot end first layer at 203C with Colorfabb PLA.

Before a print, I run the Level bed function.

Despite the 36 point test, it seems that the first layer doesn't adjust for a high spot in the middle of the bed (the heated middle area tends to be a little higher).

As a result, the prints off center of the middle adhere perfectly on the first layer, but the print area in the middle has trouble.

I'm not sure that the 36 point level bed funtion is actually working as described.

Any help would be appreciated.