Mac Mini 2020 M1 monitor issues: Shared input HDMI splitter with other devices (many devices to one monitor)

Context: I have an HDMI splitter with multiple devices connected to it (as inputs) going into one monitor (as output). I switch the active device as and when required. To elaborate, I have a Windows laptop (used for work), the Mac Mini (used for personal stuff), and a Chromebook (used for personal video calls) all sending an HDMI feed into the splitter.

The Mac Mini is connected through HDMI to this monitor - it isn't a fantastic monitor, it's only HD. But it's provided by my workplace and dominates my desk; and it is more than adequate for all my work tasks on the Windows laptop (as well as all activities on the Chromebook). Replacing the monitor is really not a recommendation I would be looking for here.

Issue 1:

• Scenario A: If none of these other devices are powered on, and if I then switch on the Mac Mini, the monitor will not wake up. Even switching out the splitter and cycling through other devices does not help.
• Scenario B: If any one of these devices is powered on prior to switching on the Mac Mini, the issue does not manifest itself. I can seamlessly switch to the Mac Mini. In a crunch, I've even connected my Android phone to the HDMI splitter and it has helped the splitter cycle through to the Mac Mini.

Issue 2: The Mac Mini randomly sends the monitor into coloured snow and then manifests Issue 1 Scenario A above (even if another device is powered on). I have to cycle out and cycle back to the Mac Mini HDMI connection on the splitter - then it restarts the monitor - and works for a brief interval before manifesting itself again. The longest timed stable duration I have observed is about 18 minutes, but on average it can time out every 5-8 minutes.

Issue 2, above, also manifests itself if I connect the Mac Mini directly to the monitor through HDMI. Albeit it's not as prevalent as it is through the splitter. Although it's rarer, it's more of a lottery to get the Mac Mini to switch the display back on.

Things I've tried by way of resolution: I have gone through multiple posts on this forum and have conducted the following activities:

• Disabled screensavers
• Disabled auto-wallpapers and have a static wallpaper kept on
• Switched around HDMI cables amongst various devices: all other devices work as expected, issues persist on the Mac Mini
• Switched around where in the HDMI splitter each device connects: all other devices work as expected, issues persist on the Mac Mini
• Reduced the display resolution: No help, if anything, that exacerbated the issue
• Reduced the screen refresh rate: Made things worse - I got a constant mini blizzard in the bottom 1/8th of the monitor
• Connected the Mac Mini directly to the monitor through HDMI (bypassing the HDMI splitter): Has not resolved the problem
• Timed the appearance of snow, there is no pattern that I can recognise
• Tracked usage to see if any applications were triggering the snow, but there's not even any correlation towards which I can point, let alone causation.

System details:

• Mac Mini M1 2020
• Memory: 8gb
• OS: macOS Big Sur Version 11.4

Would appreciate any insight and advice here - of course, other than those that call for replacing either the monitor, the HDMI splitter, or the Mac Mini itself (even if the time taken out for those responses will be appreciated deeply).