First AC4U. Those are really beautiful. The rind is super nice. Like you say, more like an alpine rind, but still really nice. I have a little bit of experience with similar cheeses, so I'll tell you what little I know. Firs a washed curd - washed rind is a bit tricky to go soft. Essentially, the runniness of the cheese is dependent upon the a couple of factors. You want to have the right surface area to volume ratio because the b. linens is producing ammonia from the outside. The more surface area you have, the more b. linens you have and therefore the more ammonia you have. This ammonia needs to soak into the whole cheese, so the more volume you have, the less runny it will get. It's a bit of a balance between how much b. linens is growing on the outside and how thick your cheese it.
I think part of your problem is that the b. linens did not really grow long enough on the rind. You don't have a bright orange, slightly tacky rind. So humidity and temperature is part of the equation. I admit that that I find this aspect of washed rinds very challenging. Especially a Reblochon and something like a port salut is tricky because you are walking a very tight line between too much and too little. But the biggest thing I can see is that you have a very thick rind on all of your cheeses, which means that it got too dry at some point. You need the b. linens to be in touch with the moist paste so that it gets the moisture it needs and also so that the ammonia can seep into the paste and soften it.
The other bit is getting the pH of paste right. With a washed curd, you are limiting the sugar supply for the starter culture. This means that you have a limited amount of acid production (which is what you want). However, the amount of whey that you exchange is critical because that decides your final pH -- and the final pH decides how runny your paste will get. Ironically, the more acid your paste, the more the ammonia will affect it (because it loses its buffing capacity). If you exchange too much whey, then you will get a firmer texture. If you exchange too little whey, then you will get a softer texture. Getting it right requires a few iterations and lots of notes, I think.
A few other things. You cheese has quite a few eyes in it. This is because of 2 factors: The first is because the whey is drained from the curd and then it is pressed. If you want to have less eyes, then you should consolidate the curd in the vat and transfer it to the mould in one big go, or a few big pieces. Similarly, you can pour the curds into the mould and then pour the whey over it. Since the holes in the cheese are full of whey, as the whey drains, no air can get in and the cheese will suck itself closed. Looking at Jim Wallace's recipe, he seems to be forming eyes on purpose. I have no idea why, because I don't think this is typical for Port Salut... (Although I admit to never having eaten it -- mostly I've had Oka, which is supposed to be similar).
The other main thing is that if the curd is *less* acidic, it will flow. If it is *more* acidic, it will be hard and stiff. So when you are putting it in the mould, normally what you want to do with a washed curd is to get it in the mold quickly and let it acidify in the mould. This lets it flow together, but then eventually get acidic enough that the cheese can get soft later when you age it. If you want the sides to slump (have that nice curve to it), then you want to remove the cheese from the mould before it has finished acidifying. Timing is important because too soon and it will slump too much. Too late and it won't slump at all. You can see in Jim' pictures that one of his cheeses hasn't even *closed* by the time he's got it in the brine... So, I'm not quite sure what he's trying to accomplish. His curved sides are due to him using a slant sided basket rather than a straight sided mould.
While I deeply respect Jim Wallace, I think this particular recipe might be a bit suspect (though I would have to look at it more closely and experiment to be sure). So if that's what you are going with, then it might be part of the problem.