I've seen Newsbin seem to chew up an excessive amount of CPU time at the end of a download; a few times (most times not):-
9632, 3,451,684,905, newsbinpro64.exe!pcre2_set_glob_escape_8+0x3a874c, Normal
3036, 3,379,353,085, tbb.dll!_TBB_machine_is_in_transaction+0xc28c, Normal
8980, 3,347,132,586, tbb.dll!_TBB_machine_is_in_transaction+0xc28c, Normal
8040, 3,309,467,018, tbb.dll!_TBB_machine_is_in_transaction+0xc28c, Normal
720, 3,279,999,903, tbb.dll!_TBB_machine_is_in_transaction+0xc28c, Normal
11072, 3,270,378,609, tbb.dll!_TBB_machine_is_in_transaction+0xc28c, Normal
10816, 3,193,361,041, tbb.dll!_TBB_machine_is_in_transaction+0xc28c, Normal
9448, 3,173,305,498, tbb.dll!_TBB_machine_is_in_transaction+0xc28c, Normal
10520, 88,032,058, newsbinpro64.exe!pcre2_set_glob_escape_8+0x3a874c, Normal
5700, 77,387,464, newsbinpro64.exe!pcre2_set_glob_escape_8+0x3a874c, Normal
5656, 77,117,706, newsbinpro64.exe!pcre2_set_glob_escape_8+0x3a874c, Normal
5620, 61,768,073, newsbinpro64.exe!pcre2_set_glob_escape_8+0x3a874c, Normal
3548, 54,830,774, newsbinpro64.exe!pcre2_set_glob_escape_8+0x3a874c, Normal
8280, 51,375,056, newsbinpro64.exe!pcre2_set_glob_escape_8+0x3a874c, Normal
^ Thread ID
^Number of cycles
^ Symbolic info
In particular the threads executing _TBB_machine_is_in_transaction+ are all running "hot". As far as I can tell it is not doing a parallel PAR2 recovery (but I could be wrong - no .1 files in the download directory).
The problem seems to fix itself after some time, but quite apparent. Not something I've seen with previous versions. I have Newsbin setup to use 8GB of memory for chunks (I have 32GB ram) to minimize disk I/O........ not 100% sure but the issue may only occur when the download size exceeds this?