There are 2 issues with your config.txt:
dtoverlay=gpio-ir,gpio_in_pin=18
you are still using "gpio_in_pin" instead of "gpio_pin" and also you can't use GPIO 18 - this is required by the I2S interface - dmesg/journal therefore prints this:
Apr 11 18:28:51 LE923zero kernel: pinctrl-bcm2835 20200000.gpio: pin gpio18 already requested by ir-receiver@12; cannot claim for 20203000.i2s
You have to connect the IR receiver to a GPIO that's not used by the DAC card, GPIO 17 should be fine, and then properly specify that in the dtoverlay line - eg gpio_pin=17
so long,
Hias