Have you recently changed its location? The plant looks fine to me...

It looks fine right now, but definitely keep an eye on it.

How do you decide when to water it?

Can you also describe the process you use to water it?

If you saying that it is 'softer', I would suspect water-retaining soil and possible damage to roots from it. Can't say for sure, just going by what you said. I see gravel top-dressing, but what kind of 'soil' is it potted in?

If there is lots of coarse perlite in your mix, it should be OK. Top-dressing should be ok too, I was just wondering about what is underneath it.

Your plant cold be OK as previous posters suggested, I personally am suspicious when someone says it is getting softer. I also see at least 2 leaves yellowing - may be normal, but maybe not. Oldest leaves of plants eventually dry up, but it shouldn't be few at the same time. If that is the case, they dry up & shrivel. If they start yellowing and are soft, it isn't typical ageing. (They could react similarly if sunburned, but I do not see that happening with your plant - only if it was put in much stronger sunlight without acclimatizing to it.)

When watering succulents, they should be watered thoroughly. Any excess water should drain thru drainage holes and if any collected in a saucer, it should be emptied asap. Potting mix should e dry deep in the pot, not only on a surface/close to surface. Using bamboo skewer or chopstick to test mix deep in the pot (3/4 deep or more) will help to determine if it is time to water or there is still enough moisture left.

If it was my plant and I suspected/saw changes, I would immediately check mix for excessive moisture (as I described). If that was OK, I would want to unpot and see the roots. Did you recently repotted it? When you did, last time, were the roots cleaned off old soil? Did they look healthy?