hsa contribution limit for one parent and two children?

HI, 

   I have hsa eligible health insurance plan, conver me and my two children, 12 and 14. I thoght my limit is 8550 for 2025. However, my  hsa custodian says my limit is 4300. is it right? I just notice when I log into my hsa account. 

worse worst scenario, if I excess my limit, what step should I take to correct? My hsa is through my work.

thanks so much, appreciate any input