Pass CATV and ethernet over single ethernet wire
Based on this AVforum thread (from 2018), forwarding a coax-delivered TV/satellite signal over Ethernet isn't possible and if it were, it would probably be a bad idea anyway. Some relevant quotes in case the link dies:

Unlike say a HDMI signal you had previously which is just one signal albeit high bandwidth satellite signals are lots of different ones on the cable. Hence you use a satellite tuner to tune into the relevant frequency.
Sky Q uses a wideband LNB which has a frequency range of 230MHz to 2359MHz so not feasible to send all these signals this cables in a different manner down a CAT cable.I'm not certain what TV carrier the OP is using, but I believe the concept is similar no matter who the carrier is. --Ed


A good friend of mine is an aerial/satellite specialist and says it's not even a good idea to extend coax with more coax! Whenever there is a break in the copper joined by couplers or whatever, the impedance can change massively affecting signal quality. He doesn't even terminate to sockets and runs cable from LMB to Sky box because of these issues; he's been burned by this too many times.

Since it seems you have conduit in your walls, your best bet would be to pull a good quality coax cable (I believe RJ56 (or is it RJ59?) is the current &quot;best&quot;) from the entry point in your house to as close to your use point as possible.
Both high-grade coax and Cat6 cables are well insulated against RF interference, and the Cat6 cables design even allows it to run next to power lines without picking up significant interference. (Note: it's still recommended to keep Ethernet cables away from power, but it's not critical in most use cases, and it's only a few inches.)