Perpetual bond aspect is not a problem. It's the callable/mandatory aspect that gets you.
Or the provisions in (not) paying the interest for a few years...
The perpetual nature means big effects in long term rate changes... maybe less so for this specific one, but if it has a fixed 5% and you buy it at above par... that will still hurt quite a bit when long rates go up...
Anyway, I learned my lesson... not touching those until they sit at 30-50...
