Hi,
I had working setup of two 1-Wire devices (DS18B20) in parasite mode.
/boot/config.txt: dtoverlay=w1-gpio,gpiopin=4,pullup=on
It stopped working right after the kernel upgrade to the latest version
Linux raspberrypi 4.19.42+ #1219 Tue May 14 21:16:38 BST 2019 armv6l GNU/Linux
Both sensors are correctly detected by the system, however reporting 85000, which is value after sensor restart. From the symptoms, it looks that the strong pull-up functionality necessary for the parasite mode is not working.

pi@raspberrypi ~ $ ls /sys/bus/w1/devices/
w1_bus_master1  28-000000429998  28-000002f1e200

pi@raspberrypi ~ $ cat /sys/devices/w1_bus_master1/28*/w1_slave
50 05 4b 46 7f ff 0c 10 1c : crc=1c YES
50 05 4b 46 7f ff 0c 10 1c t=85000
50 05 4b 46 7f ff 0c 10 1c : crc=1c YES
50 05 4b 46 7f ff 0c 10 1c t=85000

Can anybody confirm that 1-Wire devices in parasite mode are working in the latest kernel?
Note: @iz8mbw had similar problem in #348 some time ago.