Family planet amount is changing over ticks, while no attacks have been made.

(in this example we did swap 6 planets - 6 succesful attacks and 6 defeats, but this obviously had no influence)

Before tick

Score Rank: #2 Networth Rank: #5 Planets Rank: #1
Empire    Race    Score    Networth    Planets
Sgt Slappy    Thirds    27,221    1,541,772    477
Brigadier General Xe    xenon-136    20,513    1,062,435    223
Leftenant Bots    Wardancers    18,872    1,682,582    289
Lt General Orion    Marine Raiders    12,386    1,451,035    35
Major Blue    Revalons    12,130    890,736    114
Colonel DX    Camaar    9,662    1,113,766    112
Pvt Sloppy    Seconds    9,189    581,919    18
General Chaos    Camaar    5,420    362,313    99
ArmadaOfGiantZ    Partaxian    3,897    295,711    39
Tuanis    Quantam    1,296    296,062    71

Total amount of planets = 1477

After tick

Members in family #3683, THE U.S. MARINE CORPS 1916(22,42)

    Empire    Race    Networth    Planets    
    Leftenant Bots    Wardancers    1874832    293    Online!
Vice Leader    Sgt Slappy    Thirds    1546808    486    Online!
Fleet Admiral    Lt General Orion    Marine Raiders    1429544    36    Online!
Vice Leader    Colonel DX    Camaar    1093198    104    
    Brigadier General Xe    xenon-136    1068929    226    
    Major Blue    Revalons    897663    113    
Vice Leader    Pvt Sloppy    Seconds    575258    18    
    General Chaos    Camaar    358982    99    
    Tuanis    Quantam    296680    71    Online!
    ArmadaOfGiantZ    Partaxian    288082    39    

Total amount of planets = 1485

Just a hunch - maybe intra fam planet swaps are causing this. I will provide additional examples if required.