I have verified the issue against:
twrp-3.7.0_12-0-blueline.img (latest)
twrp-3.6.2_11-0-blueline.img
twrp-3.6.0_11-0-blueline.img
TWRP versions 3.3 and older no longer load on the pixel3 for me. i.e.
$ running fastboot reboot twrp-3.3.0-0-blueline.img
FAILED (remote: Error verifying the received boot.img: Invalid Parameter)
TO REPRODUCE:
$ adb reboot bootloader
$ fastboot twrp-3.7.0_12-0-blueline.img
PROBLEM: TWRP will boot. The touchscreen is disabled.
EXPECTED: TWRP will boot. The touchscreen is enabled.
WORKAROUND:
$ adb reboot bootloader
$ fastboot twrp-3.7.0_12-0-blueline.img
$ adb reboot bootloader
Select recovery
TWRP will boot. The touchscreen is enabled.
Basic issue: $ fastboot boot twrp.img on pixel3/blueline results in a non-functioning touchscreen.
Others are seeing the same issue, and have reported it in the forum: https://forum.xda-developers.com/t/touchscreen-not-working-for-twrp-3-7-0-12-with-pixel-3-blueline.4516459/
I have verified the issue against: twrp-3.7.0_12-0-blueline.img (latest) twrp-3.6.2_11-0-blueline.img twrp-3.6.0_11-0-blueline.img
TWRP versions 3.3 and older no longer load on the pixel3 for me. i.e. $ running fastboot reboot twrp-3.3.0-0-blueline.img FAILED (remote: Error verifying the received boot.img: Invalid Parameter)
TO REPRODUCE: $ adb reboot bootloader $ fastboot twrp-3.7.0_12-0-blueline.img
PROBLEM: TWRP will boot. The touchscreen is disabled. EXPECTED: TWRP will boot. The touchscreen is enabled.
WORKAROUND: $ adb reboot bootloader $ fastboot twrp-3.7.0_12-0-blueline.img $ adb reboot bootloader Select recovery TWRP will boot. The touchscreen is enabled.