Canon EOS R6 Advanced User Guide - Page 418

Lens drive when AF impossible You can specify lens operation that applies when autofocusing on a subject is not possible. [ ] Continue focus search If focus cannot be achieved with autofocus, the lens is driven to search for the precise focus. [ ] Stop focus search If autofocus starts and the focus is far off or if focus cannot be achieved, the lens drive will not be performed. This prevents the lens from becoming grossly out of focus due to the focus search drive. Caution [Stop focus search] is recommended for super telephoto lenses or other lenses that are driven over a large focus area, to avoid significant delay from focus search drive if the lens becomes greatly out of focus. 418