What the is this in Steam survey results March 2026 Linux only

There are two new entries for most popular operating systems listed for Linux Only. This coinsides with the 5% breakthrough of total Steam population (finally). But I wonder if this is an error (or April Fool's Day joke?). The two entries are just named 64 bit and 0 64 bit and its puzzling, as they have a huge percentage.

Does anyone have a clue what this is or could be?