I tested this with https::Verify-Peer false, still the same issue happens:
Fetched 1016 MB in 4min 12s (4025 kB/s) 2021/03/04 22:30:39 apt | E: Failed to fetch https://repo.pureos.net/pureos/pool/main/f/fftw3/libfftw3-double3_3.3.8-2_amd64.deb Connection timed out [IP: 138.201.228.45 443] 2021/03/04 22:30:39 apt | E: Failed to fetch https://repo.pureos.net/pureos/pool/main/s/spice-gtk/libspice-client-glib-2.0-8_0.39-1_amd64.deb Connection timed out [IP: 138.201.228.45 443] 2021/03/04 22:30:39 apt | E: Failed to fetch https://repo.pureos.net/pureos/pool/main/libs/libsodium/libsodium23_1.0.18-1_amd64.deb Connection timed out [IP: 138.201.228.45 443] 2021/03/04 22:30:39 apt | E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?