Often when puts are very deep in the money the BS curve crosses below the payoff so if you sell it you sell it for less than the intrinsic (payoff) hence it makes sense to just keep it and earn the time value.
I remember reading something about close to expiration, theta can reverse itself for ITM options. It has to do with the carry cost versus the volatility.
A simple explanation is that european style options are priced on a forward.
Thus, if interest rates are around 10% , spot is 100 and the one year put strike is 200, european option is priced on a forward around 110 (100*(1+10%)) .
Hence intrinsic value is 200-100=100 but the one year put value is 200-110=90
It's just a function of the cost of carry (CoC), however that CoC arises (including the examples you cite). If CoC > risk-free rate, delta of an option can be > 1.