Since they're indoors and this happened at the same time last year, do you think it might be the air conditioning? Does water come out of the bottom of the pot when you water?

are they getting sufficient amount of light.. are they close enough to the light.. is 8 hours sufficient???

when i ran plants under shop lights.. the lights had to be 2 or 3 inches form the plant.. and i had to run them at least 16 hours.. to make the plants grow like they are in full sun ...

im not up to speed on the new types of lights for plants... but i have to image the variables are all the same ...

ken

ps: i was always the plant guy at work.. and i must have been asked a hundred times.. why cant i grow this plant with the light under the shelf at my desk ... ummm... because your desk is 2 feet below the light.. and you turn it off when you go home...

I would put all of these in unglazed pots. All look extremely thirsty. I wonder if the roots are dying from shriveling due to lack of any moisture in the soil.

Are you using a schedule to water? Can you describe how you water?

Sempervivum would probably do better outside. They need a winter chill.

What is your water source? If it's municipal, they may be treating the water with something at the same time each year.

Are they too close to the lights? Tips look to be affected first.

It could be that something is triggering them to slow down, while you are still treating them like it is summer. Do they get any other light besides artificial lighting? Were you able to save any of the plants from last year? If so what did you do? I hope you can figure thus out since you have beautiful plants. One last thought, I have never lost a succulent from underwatering, but have graveyards full from overwatering.

Appreciate the feedback so far. I don't think it's air conditioning related, it's pretty much around 100 degrees from June through September, and they've been fine June/July.

They're top-watered the majority of the time, soaked until water comes out of the drainage hole. I'll occasionally bottom-water when time permits but not often.

Their only light source is the grow lights and they don't move throughout the year, so I ruled out sunburn. I was able to cut a few of the ones from last year and propagate them.

The municipal watering treatment is interesting though, I've never considered that. I use regular tap water from the faucet. It seems to be only impacting only select types of succulents. I've got haworthias, aloes, and cacti that were fine last year and now. Maybe the other types are susceptible to certain water treatment?

By top-watering, does that include getting the foliage wet?

another thing to consider is oedema/edema...

Oedema/edema doesn't happen because foliage is wet, but because plant takes in more water than it can transpire...plants get rained on in their habitat too...

Updated picture of an echeveria lola. The tips are turning purple and shriveling inwards. It's affecting the middle leaves first, then spreading to the lower leaves. Any ideas on what this could be? The water spots are from a fungicide spray that I sprayed after this issue began.

They are not getting enough light