haha nice, you are correct I just did a bit of searching and pulled this list from a r/sysadmin post on blocking TicTok. It's also over a year old so your mileage may vary. I had this same problem blocking WhatsApp. The IP range list was huge because of their integration with Facebook. This is why I suggested trying to use Umbrella first. Cheers!
v16a.tiktokcdn.com
ib.tiktokv.com
v16m.tiktokcdn.com
api.tiktokv.com
log.tiktokv.com
api2-16-h2.musical.ly
mon.musical.ly
p16-tiktokcdn-com.akamaized.net
api-h2.tiktokv.com
v19.tiktokcdn.com
api2.musical.ly
log2.musical.ly
api2-21-h2.musical.ly
abtest-sg-tiktok.byteoversea.com
abtest-va-tiktok.byteoversea.com
gts.byteoversea.net
isnssdk.com
lf1-ttcdn-tos.pstatp.com
muscdn.com
musemuse.cn
musical.ly
p1-tt-ipv6.byteimg.com
p1-tt.byteimg.com
p16-ad-sg.ibyteimg.com
p16-tiktok-sg.ibyteimg.com
p16-tiktok-sign-va-h2.ibyteimg.com
p16-tiktok-va-h2.ibyteimg.com
p16-tiktok-va.ibyteimg.com
p16-va-tiktok.ibyteimg.com
p26-tt.byteimg.com
p3-tt-ipv6.byteimg.com
p9-tt.byteimg.com
pull-f3-hs.pstatp.com
pull-f5-hs.flive.pstatp.com
pull-f5-hs.pstatp.com
pull-f5-mus.pstatp.com
pull-flv-f1-hs.pstatp.com
pull-flv-f6-hs.pstatp.com
pull-flv-l1-hs.pstatp.com
pull-flv-l1-mus.pstatp.com
pull-flv-l6-hs.pstatp.com
pull-hls-l1-mus.pstatp.com
pull-l3-hs.pstatp.com
pull-rtmp-f1-hs.pstatp.com
pull-rtmp-f6-hs.pstatp.com
pull-rtmp-l1-hs.pstatp.com
pull-rtmp-l1-mus.pstatp.com
pull-rtmp-l6-hs.pstatp.com
quic-tiktok-core-proxy-i18n-gcpva.byteoversea.net
quic-tiktok-proxy-i18n-gcpva.byteoversea.net
sf1-ttcdn-tos.pstatp.com
sf16-ttcdn-tos.ipstatp.com
sf6-ttcdn-tos.pstatp.com
sgsnssdk.com
tiktok-lb-alisg.byteoversea.net
tiktok-lb-maliva.byteoversea.net
tiktok-platform-lb-alisg.byteoversea.net
tiktok.com
tiktokcdn-in.com
tiktokcdn-us.com
tiktokcdn-us.com.atomile.com
tiktokcdn.com
tiktokcdn.com.atomile.com
tiktokcdn.com.c.bytetcdn.com
tiktokcdn.com.c.worldfcdn.com
tiktokcdn.com.rocket-cdn.com
tiktokd.org
tiktokv.com
tiktokv.com.c.worldfcdn.com
tiktokv.com.c.worldfcdn2.com
tlivecdn.com
ttlivecdn.com
ttlivecdn.com.c.worldfcdn.com
ttoversea.net
ttoverseaus.net
71.18.0.193 ByteDance Inc. AS396986 71.18.0.0/24 United States
71.18.0.194 ByteDance Inc. AS396986 71.18.0.0/24 United States
71.18.0.196 ByteDance Inc. AS396986 71.18.0.0/24 United States
71.18.1.224 ByteDance Inc. AS396986 71.18.1.0/24 United States
71.18.1.248 ByteDance Inc. AS396986 71.18.1.0/24 United States
5.8.92.62
161.117.70.145
161.117.71.36
161.117.71.33
161.117.70.136
161.117.71.74
216.58.207.0/24
47.89.136.0/24
47.252.50.0/24
205.251.194.210
205.251.193.184
205.251.198.38
205.251.197.195
185.127.16.0/24
182.176.156.0/24