Regular Shellac clients now not lasting

[Flickaroo]

As the title says, I've just had the second client in a week come back with the shellac coming off whole.
Both clients have been having regular shellac with no problems for many months.
Could they need a break? I'm fully trained and haven't recently done anything different.
I'm sorry I did use the search as I'm sure this has been asked before but there are so many posts to sift through.
If anyone can point me in the right direction or has an answer as to why this has suddenly happened I would be most grateful!
Thank you in advance.

 

[Faylizzie]

How long left have you got on your bulbs? Have you turned them over yet? Could be due to that possibly? What condition are their nails in? Xxxx

 

[Flickaroo]

How long left have you got on your bulbs? Have you turned them over yet? Could be due to that possibly? What condition are their nails in? Xxxx

Nails are fine.
Didn't realise you were meant to turn the bulbs? I just change when it beeps at me!
I use several different lamps depending which station I'm on so it varies.
Will try turning then?

 

[busybee32]

Check your bulb life, have you been cleaning them with anything other than a soft dry cloth?
If you bulbs are older they will lose some of their strength.
Jen xxx

 

[Kellsy]

The bulbs need turning when they get down to about 50 hours Your client won't need a break as there is no damage to the natural nail using Shellac x