I just tried v1.6 on my library, and it reports 17 albums under "Albums Not Present". The detailed report is listed below.
Two out of the 17 albums have a detailed listing of all tracks that are not present whereas the other 15 albums just list the album name.
What is the reason for these two different types of log entries?

Artur Rubinstein - Waltzes [AccurateRip DiscIDs: 014-00192771-010aac3a-a20b3e0e]

Benjamin Britten - Choral Music from King's College [AccurateRip DiscIDs: 009-0016fb6e-00993550-870b5909]

Beth Carvalho - Saudades da Guanabara [AccurateRip DiscIDs: 013-0016e2e9-00e3a0ce-9f0a9b0d]

Catherine Nardiello - A Festival of Piano Music [AccurateRip DiscIDs: 010-00143a83-009da782-8d0c440a]

Choir of Clare College, Cambridge - The Trees They Do Grow High [AccurateRip DiscIDs: 017-00302e43-025f3ff6-15126c11]

Franz Schubert - Piano Quintet "Trout" in A Major [2] [AccurateRip DiscIDs: 009-0017fe8e-00b16477-7a111a09]
Track Not Present in AccurateRip E:\Music\Franz Schubert\Piano Quintet _Trout_ in A Major [2]\01 Quintet for Piano & Strings in A,.m4a
Track Not Present in AccurateRip E:\Music\Franz Schubert\Piano Quintet _Trout_ in A Major [2]\02 Quintet for Piano & Strings in A,.m4a
Track Not Present in AccurateRip E:\Music\Franz Schubert\Piano Quintet _Trout_ in A Major [2]\03 Quintet for Piano & Strings in A,.m4a
Track Not Present in AccurateRip E:\Music\Franz Schubert\Piano Quintet _Trout_ in A Major [2]\04 Quintet for Piano & Strings in A,.m4a
Track Not Present in AccurateRip E:\Music\Franz Schubert\Piano Quintet _Trout_ in A Major [2]\05 Quintet for Piano & Strings in A,.m4a
Track Not Present in AccurateRip E:\Music\Franz Schubert\Piano Quintet _Trout_ in A Major [2]\06 Piano Trio *1 in B Flat, D 898 -.m4a
Track Not Present in AccurateRip E:\Music\Franz Schubert\Piano Quintet _Trout_ in A Major [2]\07 Piano Trio *1 in B Flat, D 898 -.m4a
Track Not Present in AccurateRip E:\Music\Franz Schubert\Piano Quintet _Trout_ in A Major [2]\08 Piano Trio *1 in B Flat, D 898 -.m4a
Track Not Present in AccurateRip E:\Music\Franz Schubert\Piano Quintet _Trout_ in A Major [2]\09 Piano Trio *1 in B Flat, D 898 -.m4a

Galina Vracheva; Serge-Etienne Freytag - Meine Lieblingslieder [AccurateRip DiscIDs: 011-000a2f15-005815cd-9105810b]

Georg Friedrich Handel - Water Music [AccurateRip DiscIDs: 022-002f81a0-02d3c13a-430c2c16]

Glenn Miller - 20 Reflective Recordings [AccurateRip DiscIDs: 020-002db4a7-029981db-240e4214]

Harlow Chorus - The Christmas Story [AccurateRip DiscIDs: 025-0037dc4c-03f64dc9-670f4119]

Ian Partridge - A Gardin for Delights, English Renaissance Lutesongs [AccurateRip DiscIDs: 019-002a08ad-02590a59-080f7913]

James Galway - Music for My Friends [AccurateRip DiscIDs: 015-00243a99-019cca4a-eb11150f]
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\01 La Flūte de Pan, for flute & pian.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\02 La Flūte de Pan, for flute & pian.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\03 La Flūte de Pan, for flute & pian.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\04 Andante Pastorale et Scherzettino.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\05 Andante Pastorale et Scherzettino.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\06 Nocturne et Allegro Scherzando fo.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\07 Nocturne et Allegro Scherzando fo.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\08 Carnival of Venice for flute & or.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\09 Andante and Rondo for flute, viol.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\10 Andante and Rondo for flute, viol.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\11 Cantabile and Presto, for flute &.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\12 Cantabile and Presto, for flute &.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\13 Fantasy for flute & orchestra.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\14 Il Pastore svizzero, for flute &.m4a
Track Not Present in AccurateRip E:\Music\James Galway\Music for My Friends\15 Concertino for Flute & Piano (or.m4a

Johannes Brahms; Camille Saint-Saėns - Violin Concertos [AccurateRip DiscIDs: 006-0012a86f-005ebf34-56101006]

Olivier Messiaen - Olivier Messiaen Plays (Organ) [AccurateRip DiscIDs: 010-001bdc9d-00daf53d-7a10b70a]

Tom Lehrer - Tom Lehrer In Concert [AccurateRip DiscIDs: 001-00001e28-00003c51-02006601]

University of Western Ontario - Convocation Brass [AccurateRip DiscIDs: 020-002f1b21-02c3f82b-3f0ff314]

Wolfgang Amadeus Mozart - Violin Concerto No. 2 [AccurateRip DiscIDs: 006-000a2d1a-00357f4c-4a09ab06]