Hi Nathalie
no, it's not the receiver, it's the software which can run 10.14.x max. EyeTV 3.x is 32 bit and won't work on 64-bit-only Systems such as 10.15.x and newer... I therefore use a old MacMini 2011 with 10.13.x , not having to upgrade to EyeTV 4.x.
hope this helps - Pit