Pilog not updating, settings not saving via web interface, dhcp not working

[dankcushions]

It seems I have a lot of issues with my fairly generic pihole setup on a Pi3 running Debian Buster, with pihole installed via the command line:
Linux raspberrypi 5.4.51-v7+ #1333 SMP Mon Aug 10 16:45:19 BST 2020 armv7l GNU/Linux

DHCP is disabled on my Virgin Media Super Hub 2 router, and enable via the pihole web interface, but doesn't seem to be allocating IPs any more. In an attempt to diagnose this, I restarted the pihole, tried to look at the various diagnostics tools, but none seem to be working properly (debug log never gets created, real-time log doesn't show anything, etc).

I can access the pihole via command line, but if I look at the pihole.log, it doesn't seem to have logged anything for hours (even thought I've rebooted since):

ep 22 11:51:24 dnsmasq[21462]: query[A] nrdp.prod.cloud.netflix.com from 192.168.0.151
Sep 22 11:51:24 dnsmasq[21462]: forwarded nrdp.prod.cloud.netflix.com to 8.8.4.4
Sep 22 11:51:24 dnsmasq[21462]: reply nrdp.prod.cloud.netflix.com is <CNAME>
Sep 22 11:51:24 dnsmasq[21462]: reply nrdp.prod.cloud.dradis.netflix.com is <CNAME>
Sep 22 11:51:24 dnsmasq[21462]: reply nrdp.prod.cloud.eu-west-1.internal.dradis.netflix.com is <CNAME>
Sep 22 11:51:24 dnsmasq[21462]: reply dualstack.apiproxy-nrdp-prod-nlb-3-a71b4c004683cf09.elb.eu-west-1.amazonaws.com is 54.155.136.132
Sep 22 11:51:24 dnsmasq[21462]: reply dualstack.apiproxy-nrdp-prod-nlb-3-a71b4c004683cf09.elb.eu-west-1.amazonaws.com is 54.77.110.160
Sep 22 11:51:24 dnsmasq[21462]: reply dualstack.apiproxy-nrdp-prod-nlb-3-a71b4c004683cf09.elb.eu-west-1.amazonaws.com is 54.220.170.166
Sep 22 11:53:07 dnsmasq[21462]: exiting on receipt of SIGTERM

Debug Token:

pi@raspberrypi:~ $ pihole -d
/usr/local/bin/pihole: line 16: syntax error near unexpected token `)'
/usr/local/bin/pihole: line 16: `??gk?????W
?j?p??н9????p6=O?B\?ß/V???-???hl)??KèP?˕?h2?ʌa?pp???YSR??w????Ҽd?3???q^Y\?{??낵?g7?pQ?????Y
                                                                                           1R?L
                                                                                               ???PT??-0O??$.z?w?$ᘟ;??????F%?x???)f]zO`G?ɨn2_?m{????Y??1,`??Z?a2???"?u?E?4??P???t,0?!rg??,D)??
h\??(&?K?+??bҎ???d????n?ho??$??T?A???H?+$???\N?MD$??%?????????H??Nw?N???N?????ǃ??????H?n'

[DanSchaper]

If that is really what /usr/local/bin/pihole looks like then you have filesystem corruption and it's time for a new SDcard.

[dankcushions]

yup, looking that way have binned the SD card and have tried another. so far so good...