vorato I'm stumped.
The ePSA checked out with no hardware problems, and the problem did not exist running under Windows. It doesn't look like a hardware failure (despite the blinking Caps Lock) and points toward a Linux/Solus issue.
The Intel components (i3-1115G4, Intel Mesa integrated UHD graphics, and so on) are recent, but old enough that Intel-supplied drivers are (to my best knowledge) incorporated in the 5.14 kernel. I can't find any reports of issues with 11th Gen Intel GPU/CPU Linux incompatibilities. Problems were reported with older kernel versions, but nothing with version 5.11 or later that I can find.
The only components I see that might be causing an issue are the Realtek wifi/bluetooth/camera components. Realtek is not good about providing drivers for Linux, but the rtl8821ce driver (probably a community build) seems to be installed. Wifi issues have been reported with the rtl8821ce on other distros but cause connectivity issues rather than freeze-ups.
Looking at the Dell support pages for the 15-1520, I see recent (January/February) firmware updates, both BIOS and NVME drives:
It is possible that updating firmware (particularly for your specific M.2 NVMe) might resolve the issue, but updating firmware is a tedious process (reinstall Windows, then update firmware, then reinstall Solus) and I'm not sure whether the cost/benefit lines up until other possibilities have been explored and exhausted.
I'm a bit aggressive when on the triage hunt (that's how my friends would describe it; more normal people might just call it "obsessive" or "nuts"), so I might (if it were my computer) try to determine whether the issue is specifically Budgie-related by installing one of the other Solus DE's, and then, if the problem also occurs with that DE, I might try to determine whether the issue is specifically Solus-related or more generally Linux-related by installing Ubuntu 21.10 (to get relatively current drivers) and see what happens then. But I'm not suggesting that you do that at this point.
Not having found much in the way of internet discussions of the 15-3520 specifically, I'm going to poke around looking for 11th Gen Linux issues in a more general sense, paying particular attention of BIOS settings (hardware acceleration and so forth) to see if I stumble across anything.
Meanwhile, I hope that this thread might attract someone who might point you in a better direction.
