I've worked at a few nursing homes and they all had a history of firing the CNAs routinely, there were very few aides who had been there for a very long time. I remember the first time I got hired at LTC, an employee who had been there for 9 months warned me about how the place fired CNAs almost in droves, and that I probably won't be around much longer.
She was right.
This is one of the reasons why I have strayed away from nursing homes and tried Homehealth. The only downside is that you may not always get consistent hourly work, but as long as you always show up to duty, you can stay employed a lot longer than at a nursing home.