I did the install from nextcloud-22.1.0.tar.bz2 on a vendor VM, running Debian Buster, and already established a bare-bones apache2 server, TLD domain name, with Letsencrypt - all apparently functioning properly.
The Nextcloud install went smoothly, and everything seems to be working, but the login fields do not appear. I put apache2 in debug mode and this is what I see in the error log:
Mon Sep 27 21:09:57.739756 2021] [ssl:debug] [pid 1080] ssl_engine_kernel.c(2235): [client 71.233.118.160:47968] AH02041: Protocol: TLSv1.3, Cipher: TLS_AES_256_GCM_SHA384 (256/256 bits)
[Mon Sep 27 21:09:57.739866 2021] [socache_shmcb:debug] [pid 1080] mod_socache_shmcb.c(495): AH00831: socache_shmcb_store (0x0a → subcache 10)
[Mon Sep 27 21:09:57.739882 2021] [socache_shmcb:debug] [pid 1080] mod_socache_shmcb.c(849): AH00847: insert happened at idx=2, data=(434:466)
[Mon Sep 27 21:09:57.739886 2021] [socache_shmcb:debug] [pid 1080] mod_socache_shmcb.c(854): AH00848: finished insert, subcache: idx_pos/idx_used=0/3, data_pos/data_used=0/650
[Mon Sep 27 21:09:57.739890 2021] [socache_shmcb:debug] [pid 1080] mod_socache_shmcb.c(516): AH00834: leaving socache_shmcb_store successfully
[Mon Sep 27 21:09:57.740008 2021] [socache_shmcb:debug] [pid 1080] mod_socache_shmcb.c(495): AH00831: socache_shmcb_store (0xed → subcache 13)
[Mon Sep 27 21:09:57.740026 2021] [socache_shmcb:debug] [pid 1080] mod_socache_shmcb.c(849): AH00847: insert happened at idx=0, data=(0:32)
[Mon Sep 27 21:09:57.740030 2021] [socache_shmcb:debug] [pid 1080] mod_socache_shmcb.c(854): AH00848: finished insert, subcache: idx_pos/idx_used=0/1, data_pos/data_used=0/216
[Mon Sep 27 21:09:57.740034 2021] [socache_shmcb:debug] [pid 1080] mod_socache_shmcb.c(516): AH00834: leaving socache_shmcb_store successfully
[Mon Sep 27 21:09:57.813817 2021] [ssl:info] [pid 1102] (32)Broken pipe: [client 71.233.118.160:47958] AH01993: SSL output filter write failed.
Could this be a bug of some kind? The machine seems to be configure properly…