Solution
[Movie Servo AF speed] setting of the EOS 6D Mark II functions with a combination of [Movie Servo AF] set to [Enable], [AF method] set to [Live 1-point AF], and use of the lenses supporting the slow focus transition for movie shooting as listed below.
(USM lenses released in and after 2009 and STM lenses are compatible.)
EF24mm f/2.8 IS USM
EF28mm f/2.8 IS USM
EF40mm f/2.8 STM
EF35mm f/1.4L II USM
EF35mm f/2 IS USM
EF50mm f/1.8 STM
EF100mm f/2.8L Macro IS USM
EF300mm f/2.8L IS II USM
EF400mm f/2.8L IS II USM
EF400mm f/4 DO IS II USM
EF500mm f/4L IS II USM
EF600mm f/4L IS II USM
EF8-15mm f/4L Fisheye USM
EF11-24mm f/4L USM
EF16-35mm f/2.8L III USM
EF24-105mm f/3.5-5.6 IS STM
EF24-105mm f/4L IS II USM
EF16-35mm f/4L IS USM
EF24-70mm f/2.8L II USM
EF24-70mm f/4L IS USM
EF70-200mm f/2.8L IS II USM
EF70-300mm f/4-5.6L IS USM
EF70-300mm f/4-5.6 IS II USM
EF100-400mm f/4.5-5.6L IS II USM
EF200-400mm f/4L IS USM Extender 1.4x
NOTE
Including overseas models.