Crosstalk between mic and headphones when using splitter and combo jack

I've got a pair of DT770 headphones, as well as a Sony ECM-LV1 mic clipped to the cable of the headphones, which run through a splitter to a combo headphone jack on a USB-C dock (Lenovo Universal USB-C Dock DK1633). People have been complaining for a long time that my game sound leaks into my mic, which I just ignored. I'd like to fix that issue now.

I started off by replacing the splitter, which didn't resolve the issue.

However, I noticed that the issue even occurs if I disconnect my mic from the splitter (from a bit of Googling, I heard this issue is called crosstalk). I tried the combo jack on my laptop (ASUS ROG Strix G15 G513RM), and the issue is even worse over there. The issue also occurs on my M1 MacBook Air. After being a bit fed up, I went out and bought a cheap USB sound card (Sound Blaster Play 3) which has seperate headphone and mic jacks, and the issue resolved itself as long as I the headphones and mic connected to separate plugs.

Whilst this is an okay solution, is there a way to get them working on a combo jack? I regularly switch these headphones back and forth between my PC and PS5, and it takes just a little bit longer to disconnect and reconnect the splitter for my controller each time.