Pi Zero, AdaFruit 3.5" touchscreen and the UART GPS

Hi,

I tested the UART GPS (Ultimate GPS breakout) on my Pi Zero before adding the piTFT and got it to work nicely :)
Since adding the Adafruit kernel for the TFT, I can not get any data from the UART.

My cmdline.txt is : dwc_otg.lpm_enable=0 console=tty1 root=PARTUUID=8ed54187-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait fbcon=map:10 fbcon=font:VGA8x8

and config.txt:
# Enable UART
enable_uart=1

# --- added by adafruit-pitft-helper Mon 5 Jun 06:07:10 UTC 2017 ---
[pi1]
device_tree=bcm2708-rpi-b-plus.dtb
[pi2]
device_tree=bcm2709-rpi-2-b.dtb
[all]
dtparam=spi=on
dtparam=i2c1=on
dtparam=i2c_arm=on
dtoverlay=pitft35-resistive,rotate=270,speed=16000000,fps=20
dtoverlay=pitft35-resistive,touch-swapxy,touch-invx
# --- end adafruit-pitft-helper Mon 5 Jun 06:07:10 UTC 2017 ---

Is it the overlays that cause the problem?
How do I solve it and get access to the GPS breakout via UART?

Thanks
Ian

according to the pinout, there is no reason why the overlay would interfere, but I haven’t looked at the dts source in details to confirm.

What Zero is this on however? regular revision 1.3 without BT/WIFI?