[Solved] Ubuntu apt repo broken?

It looks like the index might be out of date relative to the packages - here's what I'm seeing when trying to perform a fresh install on either 22-04 or 24-04:

Get:1 removed link jammy/main amd64 carbonio-icu amd64 74.2-2jammy [15.2 MB]
Err:1 removed link jammy/main amd64 carbonio-icu amd64 74.2-2jammy
File has unexpected size (15238008 != 15237120). Mirror sync in progress? [IP: 18.245.96.31 443]
Hashes of expected file:
- SHA256:56ecc5d0d43d9170fe5ead47a932463e66590955f99ccb24334480e232e23c76
- SHA1:a806a618126dea5ab843d27e052bcee70f541da2 [weak]
- Filesize:15237120 [weak]
Get:2 removed link jammy/main amd64 carbonio-krb5 amd64 1.21.2-2jammy [1,600 kB]
Err:2 removed link jammy/main amd64 carbonio-krb5 amd64 1.21.2-2jammy
File has unexpected size (1600372 != 1600116). Mirror sync in progress? [IP: 18.245.96.31 443]
Hashes of expected file:
- SHA256:ec4516c47a3d132928490a7e9e2963bf647c69ad5cfaa8e4718d613cb38b8d31
- SHA1:a49246eef244c4c7fc0999274c57bdcde7a01cf7 [weak]
- Filesize:1600116 [weak]
Get:3 removed link jammy/main amd64 carbonio-openssl amd64 3.0.16-1jammy [3,207 kB]
Err:3 removed link jammy/main amd64 carbonio-openssl amd64 3.0.16-1jammy
File has unexpected size (3207380 != 3207312). Mirror sync in progress? [IP: 18.245.96.31 443]
Hashes of expected file:
- SHA256:b1f709896179aaadf2103e0280dd28079c1b813f8dae8eef5eac70c2777d3f73
- SHA1:ffbf600e21d63db1259783bdf0a613a8974c8c74 [weak]
- Filesize:3207312 [weak]
Get:4 removed link jammy/main amd64 carbonio-curl amd64 8.13.0-1jammy [1,118 kB]
Err:4 removed link jammy/main amd64 carbonio-curl amd64 8.13.0-1jammy
File has unexpected size (1120996 != 1118190). Mirror sync in progress? [IP: 18.245.96.31 443]
Hashes of expected file:
- SHA256:4d29de68282285d0960b19e0f8498cbdf572617b2616b900802e1b0a731e6387
- SHA1:ff2bb3ec62ef62a78be20b5e4330d7a640d6226e [weak]
- Filesize:1118190 [weak]
Get:5 removed link jammy/main amd64 carbonio-jemalloc amd64 5.3.0-3jammy [12.9 MB]
Err:5 removed link jammy/main amd64 carbonio-jemalloc amd64 5.3.0-3jammy
File has unexpected size (12923354 != 12915268). Mirror sync in progress? [IP: 18.245.96.31 443]
Hashes of expected file:
- SHA256:8d9af5536d8a16fee361c2d962473558ec6a8bc48464652cb12b1c18e3851d58
- SHA1:4bfaab9a07b72934cfa57a474ff67c864755446d [weak]
- Filesize:12915268 [weak]

This has been happening for hours, and I can't see any new releases getting pushed via github.. so I'm guessing something's gone sideways!

Does anyone know if there's an alternative mirror?