cannot reach last page in some topics

[wlseries]

is there a reason why some topics, when I click the last page or pages, I only can read the 3rd or 4th last page?

like last page is 201

I only can access 197. when i click 198, I get redirected back to 197.

Notice for a while liao no idea why

[Caffeine17]

Testing123456789