Guidance is one of Roblox's problems. A too-expensive valuation is another.Shares of online gaming platform Roblox Corporation (RBLX -21.98%) tumbled 21% through 10:35 a.m. ET Thursday despite beating on both sales and earnings this morning.Heading into the Q1 2024 report, analysts had forecast Roblox would lose $0.53 per share on$923 million in quarterly bookings. (A proxy for revenue, Roblox's bookings consist of sales of Robux, virtual currency that will eventually be spent and converted into revenue.) ...