In many situations, "we do not recommend" can be taken to mean "we recommend that you don't do it." for example. But, this isn't always the case: on medicine in the UK, you will often see the phrase "Not recommended for pregnant women or women who are breastfeeding." What this actually means is "We haven't tested it with pregnant or breastfeeding women, so we don't know if there will be any side effects on the baby, so we are not able to recommend it.. However, it could be perfectly safe.
This is different to the alternate phrase often seen, "Not suitable for pregnant women or women who are breastfeeding.". This is saying "We do have some specific evidence which suggests that it's bad for pregnant/breastfeeding women." This is like saying "We recommend that pregant women do not use this medicine"
So, in the first instance "not recommended" literally means just that: that "We are not able to recommend that you use it.", and it's different to the second instance which means "We recommend that you do not use it".
So, to not recommend that you do something isn't always the same as recommending that you do not do something.