Level 28 - 28%
Level 29 - 28%
Level 30 - 30%
Looks like a small typo happened in the configs. 29 should be 29% I'm guessing, lol.

I dont see any text like that in game. Can you provide a screenshot?

Level 28 - https://i.imgur.com/Vch482z.jpg
Level 29 - https://i.imgur.com/0OLhhV7.jpg
Level 30 - https://i.imgur.com/IolOZV4.jpg

My module level is 29 and they also only have 28% speed, energy cost, and productivity.

that is really peculiar because the items are generated by code and thus there can be no typos

for i = 1, 100, 1 do
data:extend({
{
type = "module",
name = "alien-hyper-module-" .. i,
icon = "alien-module/graphics/alien-hyper-module-1.png",
icon_size = 32,
flags = { "goes-to-main-inventory" },
subgroup = "alien-hyper-module",
category = "alien-module",
tier = i,
order = "a-" .. i,
stack_size = 50,
effect =
{
consumption = { bonus = 0.01 * i },
speed = { bonus = 0.01 * i },
productivity = { bonus = 0.01 * i }
},
},
})
end

That does make it really weird. Wonder why mine did that then.

It might be a floating point rounding error. Try i/100 instead of 0.01*i.

That does not change the value being 28%. i also noticed the same happening with module level 57 and 58.

Good hint with the floating point issue, but is suspect it was actually inside Factorios code, when i say bonus = 0.01001 * i the percentages are correct, i think internally factorio sas bonus = round to two decimals by just math.floor the value, so 0.28 gets rounded to 0.28 and 0.28999999999999999999 to 0.28 as well