Chat w Dell and see if they advise you to open it up to inspect system fan yourself or have a tech visit.
Hi,  I have bought a new Dell 7090 UFF about 3 weeks ago. 11th Gen Intel(R) Core(TM) i7-1185G7 @ 3.00GHz 3.00 GHz, 16,0 GB, with 2 HHD's: one 0,5 TB SSD and one 1TB SSD Works fine, but the fan generates a ticking sound after power-up, during some  minutes. Also when the processor has to perform (image-processing), the ticking recommences. Next to the fact it is quite irritating, having this 'ticker' on my desk, I am worried that the machine may malfunction after a period.  Thanks for any input or equal experiences... Regards,     
Optiflex 7090 UFF fan ticking sound