I've had the same problem on generation after generation of Lenovo X1's...out of the box, the laptops always crash sometime after entry to sleep. It's inevitably the (Intel) wifi driver + modern standby, and it can be quite subtle to track down.

On my current iteration (Lenovo P1 with Intel AX211), the failure also requires some other device to try to talk to the laptop while it's being put to sleep. Anecdotally sleep tends to fail harder/more often on public networks, perhaps because there's more adversarial traffic scanning computers and waking the device up.

In the end, I really don't even understand why anyone would want their wifi driver responding to network packets when the device is asleep - given that these chips have DMA access via PCI to host memory (unless the IOMMU is configured, which is not a given) - this feature is equivalent to a persistent, always-on remote back door into your RAM, even when your machine is "off". Of course this requires an exploitable CVE in your wifi stack, but there is a constant stream of CVEs and obscure "remote management features", at least in the Intel drivers.

My solution in the end has been to just remove the wifi module from the motherboard (or in cases when it's soldered down, disable the driver by deleting it entirely) and then use an external USB wifi dongle. It's been almost a year now and no sleep issues, no more randomly heating up my backpack, and in public environments like e.g. hotels I don't worry as much because I unplug the wifi card from the laptop when I'm done with it. I had to go with the nuclear option because some updater somewhere is pretty eager about discovering the presence of the wifi device and "helpfully" re-enabling it, I suspect it's the Lenovo Vantage tool.

The external USB device is slightly inconvenient but at least I don't get woken up in the middle of the night by my laptop fan spinning up mysteriously anymore (OK not entirely true, the malware scan will trigger at night and spin up the fans but at least I know what's causing that...).