Entering waypoints on the F10 map

OK, we've seen it often enough now. You go to the F10 map, somehow add a marker with a label by magical means that the RIO can use as a waypoint or is being used by the Viggen's data cartridge to generate a flight plan

Now the $ 1,000,000 question is: How?

Seriously, I'm just sitting in the Viggen and trying to figure out how to place mark labels on the map, couldn't find anything via search though, tried the mark labels buttons, but nothing makes it happen in either state when I right or even middle click the map (left grabs for panning around), switched rulers on/off as well, checked options - gameplay - F10 map user marks being on. Not even the [DCS]\Docs\DCS User Manual EN.pdf covers it. It doesn't even have the mark label buttons in the screenshot yet

Just asking here since the Tomcat will use this feature and probably a lot more people keep pressing their MiG-28 keys here rather than in the Viggen section...

Now the $ 1,000,000 question is: How?

1. "left click" the F10 map "Mark Label" icon

2. "left click" on the location where you want to place it

3. "left click" on it's text box and type what you want i.e. B1, B2, M3 or ATTACK, etc.

https://forums.eagle.ru/showpost.php?p=3695274&postcount=2

Step 2 doesn't seem to work as I don't get a text box or anything where I could enter something by doing so...

And I just checked if the setting's being overridden by my mission...

["userMarks"] = true,

Edit: After having DCS shut down to check the mission I thought I'd give it a try again, and out of a sudden it worked as expected. I have a strong suspicion that this is an issue related to this since it's basically the mouse cursor which didn't work correctly in the first place...