format result incorrect while digits are mass

[lushevol]

numbro("123456789012345678901234567890").format({ mantissa: 2, optionalMantissa: true }) expect to return "123456789012345678901234567890" but returns "123456789012345680000000000000"

It can be reproduced on numbro playground,

check with link below
https://numbrojs.com/try-me.html?lang=en-US&value=123456789012345678901234567890&format=%7B%22mantissa%22%3A2%2C%22optionalMantissa%22%3Atrue%7D