I can see debug log entries for the deletion which appear to indicate that it was successful. The relevant ones are in bold. I've left in the intervening irrelevant ones in case there is anything that people think is relevant. I made two attempts to delete the entry, from different PCs, about half an hour apart.
2024-11-25 10:25:58.061 [ INFO]:dvr: delete entry c5be03318209246ce5b3d5acfb80277f "Last Word" on "704 BBC Radio 4" start time 2024-11-24 20:24:30, scheduled for recording by "192.168.1.71", retention "On file removal" removal "Forever"
2024-11-25 10:26:58.053 [ INFO]:dvr: entry df3119786ac5c3d04641e988e1d6ad37 "Last Word" on "704 BBC Radio 4" starting at 2024-11-24 20:24:30, with broadcast id "crid://fp.bbc.co.uk/m/16VGI", scheduled for recording by "192.168.1.71"
2024-11-25 10:29:30.006 [ INFO]:dvr: "Classic Casualty" on "020 U&Drama" recorder starting
2024-11-25 10:29:30.008 [ INFO]:mpegts: 545.833MHz in Terrestrial - tuning on Hauppauge WinTV Dual (1) (DVB-T2) (Silicon Labs Si2168) #0
2024-11-25 10:29:30.008 [ INFO]:subscription: 0048: "DVR: Classic Casualty" subscribing on channel "020 U&Drama", weight: 500, adapter: "Hauppauge WinTV Dual (1) (DVB-T2) (Silicon Labs Si2168) #0", network: "Terrestrial", mux: "545.833MHz", service: "U&Drama", profile="pass", username=""
2024-11-25 10:30:00.060 [ ERROR]:pass: /srv/ext/Videos/Classic Casualty/Classic Casualty-20241125-1035-020 U&Drama.ts: Unable to change permissions -- Operation not permitted
2024-11-25 10:30:00.061 [ INFO]:dvr: /srv/ext/Videos/Classic Casualty/Classic Casualty-20241125-1035-020 U&Drama.ts from adapter: "Hauppauge WinTV Dual (1) (DVB-T2) (Silicon Labs Si2168) #0", network: "Terrestrial", mux: "545.833MHz", provider: "<N/A>", service: "U&Drama"
2024-11-25 10:30:00.061 [ INFO]:dvr: # type lang resolution aspect ratio sample rate channels
2024-11-25 10:30:00.061 [ INFO]:dvr: 1 MPEG2VIDEO ? ?
2024-11-25 10:30:00.061 [ INFO]:dvr: 2 MPEG2AUDIO eng 96000 ?
2024-11-25 10:30:00.061 [ INFO]:dvr: 3 MPEG2AUDIO eng 96000 ?
2024-11-25 10:30:00.061 [ INFO]:dvr: 4 DVBSUB eng
2024-11-25 10:30:29.123 [ INFO]:dvr: entry b458b0d9930f0f29edebc9c97e483e52 "Classic Casualty" on "020 U&Drama" starting at 2024-12-02 10:44:30, with broadcast id "crid://bds.tv/QQIWGJ", scheduled for recording by "192.168.1.71"
2024-11-25 10:30:35.008 [WARNING]:epggrab: UK: Freeview - data completion timeout for 545.833MHz in Terrestrial
2024-11-25 10:30:35.008 [WARNING]:epggrab: EIT: EPG Grabber - data completion timeout for 545.833MHz in Terrestrial
2024-11-25 10:30:35.008 [WARNING]:epggrab: UK: Freesat (EIT) - data completion timeout for 545.833MHz in Terrestrial
2024-11-25 10:30:35.008 [WARNING]:epggrab: UK: Freesat - data completion timeout for 545.833MHz in Terrestrial
2024-11-25 10:32:36.582 [ INFO]:dvr: "The Listeners" on "101 BBC One Yk&Li HD": Updated (u)
2024-11-25 10:54:54.409 [ INFO]:dvr: delete entry df3119786ac5c3d04641e988e1d6ad37 "Last Word" on "704 BBC Radio 4" start time 2024-11-24 20:24:30, scheduled for recording by "192.168.1.71", retention "On file removal" removal "Forever"
2024-11-25 10:55:54.399 [ INFO]:dvr: entry 3409ee185fa7dc964f321e3f16ab2567 "Last Word" on "704 BBC Radio 4" starting at 2024-11-24 20:24:30, with broadcast id "crid://fp.bbc.co.uk/m/16VGI", scheduled for recording by "192.168.1.71"