Why is the max loss the depreciation of the stock you bought to the strike of the put, and the premium? The premium is clear, you lose it if you cannot exercise the option, because it is anyway a price you paid.
I thought that in this case the max loss is only the premium?
The maximum loss on a protective put – a portfolio comprising a put option and a share of stock – is the maximum loss on the put option plus the maximum loss on the share of stock (because the maxima can occur simultaneously).