I heard that the effects of Ulthera usually last a year, but are there people who get it done again after only six months?

After getting Ultherapy last year, I loved the feeling of my jawline and face tightening up so much that I was happy every time I looked in the mirror.
However, about 8 months after the procedure, that initial tight feeling is gradually loosening, and I feel like it is returning to its original state.
I heard that the effects of Ultherapy usually last from a year to as long as a year and a half, but I’m already starting to wonder if I should get it done again.
There is a saying that receiving treatments too frequently, at intervals of 6 or 8 months, before the maintenance period is even over, can actually be harmful because it causes scarring in the underlying fascia (SMAS) or excessive stimulation.
I’ve heard from experts that there could be side effects, such as thinning of the skin or a decrease in elasticity. What is the actual recommended treatment cycle?
I am wondering if I need to strictly adhere to a one-year cycle, or if it is acceptable to get a light touch-up in specific areas when I start to feel sagging.
The cost is a burden if I get it done frequently, but I'm also secretly worried that my skin might develop a resistance to the procedure and the effect might diminish over time.
For those who manage their care consistently and regularly, I would appreciate it if you could share your scheduling know-how on how often you usually visit the clinic.