It is, unfortunately, a bug. An object at the height of Mitterand Hollow, orbiting a planet with the mass of New Africa, should go around in at least 90 minutes, not 90 seconds.
What I suspect has happened is that old data from the FE2 system map (the layout of the Epsilon Indi system is a legacy from the previous Elite games), where everything was measured in AU, has been copied directly into ED, where everything is measured in Ls. The game is therefore trying to calculate the orbital parameters of a moon that's 500 times closer than it should be. A moon that close to the planet would actually be orbiting inside the planet, and the game knows that's impossible, so it's parked the moon at the minimum allowed distance for a moon (just outside the Roche Limit) but kept the rest of the orbital parameters the same - such as the ludicrously short period length and resultantly high orbital speed.
If you want to find a procedurally-generated planet with a similar orbital period, you'll have to try to find a planet that's orbiting real, real close to a black hole. I've explored dozens of black hole systems and never found a planet that close yet. Such planets are either impossible or really, really improbable.
