Tvheadend

So I'm trying to get my TVheadend setup working again. Currently running version 4.2.8-36 on Debian Stretch, kernel version 4.9.0-19-amd64. My server ran fine using a PCTV 292e stick for ages, but one day the tuner stick died. I finally managed to buy a new one that arrived today, but no matter what I try I can't get it to pick up any services. When I run a scan every single service comes back as FAIL and this is all I get in the logs:

2022-08-11 12:33:41.518 mpegts: 714MHz in DVB-T Network - tuning on Silicon Labs Si2168 #0 : DVB-T #0
2022-08-11 12:33:41.519 subscription: 001F: "scan" subscribing to mux "714MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "DVB-T Network", service: "Raw PID Subscription"
2022-08-11 12:33:46.518 mpegts: 714MHz in DVB-T Network - scan no data, failed
2022-08-11 12:33:46.518 subscription: 001F: "scan" unsubscribing
2022-08-11 12:33:46.519 mpegts: 682MHz in DVB-T Network - tuning on Silicon Labs Si2168 #0 : DVB-T #0
2022-08-11 12:33:46.519 subscription: 0021: "scan" subscribing to mux "682MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "DVB-T Network", service: "Raw PID Subscription"
2022-08-11 12:33:51.519 mpegts: 682MHz in DVB-T Network - scan no data, failed
2022-08-11 12:33:51.519 subscription: 0021: "scan" unsubscribing
2022-08-11 12:33:51.519 mpegts: 634MHz in DVB-T Network - tuning on Silicon Labs Si2168 #0 : DVB-T #0
2022-08-11 12:33:51.519 subscription: 0023: "scan" subscribing to mux "634MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "DVB-T Network", service: "Raw PID Subscription"
2022-08-11 12:33:56.519 mpegts: 634MHz in DVB-T Network - scan no data, failed
2022-08-11 12:33:56.519 subscription: 0023: "scan" unsubscribing
2022-08-11 12:33:56.519 mpegts: 562MHz in DVB-T Network - tuning on Silicon Labs Si2168 #0 : DVB-T #0
2022-08-11 12:33:56.519 subscription: 0025: "scan" subscribing to mux "562MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "DVB-T Network", service: "Raw PID Subscription"
2022-08-11 12:34:01.519 mpegts: 562MHz in DVB-T Network - scan no data, failed
2022-08-11 12:34:01.519 subscription: 0025: "scan" unsubscribing
2022-08-11 12:34:01.519 mpegts: 690MHz in DVB-T Network - tuning on Silicon Labs Si2168 #0 : DVB-T #0
2022-08-11 12:34:01.519 subscription: 0027: "scan" subscribing to mux "690MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "DVB-T Network", service: "Raw PID Subscription"
2022-08-11 12:34:06.519 mpegts: 690MHz in DVB-T Network - scan no data, failed
2022-08-11 12:34:06.519 subscription: 0027: "scan" unsubscribing
2022-08-11 12:34:06.519 mpegts: 722MHz in DVB-T Network - tuning on Silicon Labs Si2168 #0 : DVB-T #0
2022-08-11 12:34:06.519 subscription: 0029: "scan" subscribing to mux "722MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "DVB-T Network", service: "Raw PID Subscription"
2022-08-11 12:34:11.519 mpegts: 722MHz in DVB-T Network - scan no data, failed
2022-08-11 12:34:11.519 subscription: 0029: "scan" unsubscribing
2022-08-11 12:34:11.519 mpegts: 658MHz in DVB-T Network - tuning on Silicon Labs Si2168 #0 : DVB-T #0
2022-08-11 12:34:11.520 subscription: 002B: "scan" subscribing to mux "658MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "DVB-T Network", service: "Raw PID Subscription"
2022-08-11 12:34:16.519 mpegts: 658MHz in DVB-T Network - scan no data, failed
2022-08-11 12:34:16.519 subscription: 002B: "scan" unsubscribing
2022-08-11 12:34:16.520 mpegts: 754MHz in DVB-T Network - tuning on Silicon Labs Si2168 #0 : DVB-T #0
2022-08-11 12:34:16.520 subscription: 002D: "scan" subscribing to mux "754MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "DVB-T Network", service: "Raw PID Subscription"
2022-08-11 12:34:21.520 mpegts: 754MHz in DVB-T Network - scan no data, failed
2022-08-11 12:34:21.520 subscription: 002D: "scan" unsubscribing

Every mux configured (UK-EmleyMoor) just comes back as "scan no data, failed" with no additional information.

I've even tried a clean setup but that's made no difference. Like I said before, it used to work fine, but after replacing the tuner it broke.

Any thoughts on what could have broken?