Player or mob near well-lit blaze spawner allows spawning despite high light level

[TupeloSchneck]

Using 1.14.3-forge-27.0.50, I put a torch on every square of a platform around a blaze spawner.  This should prevent blaze spawning since the light level is > 11 everywhere they can spawn.  I can stand off the side of the 9x9 platform (more than 4 blocks away from the spawner) and no blazes spawn, for minutes.  But if I step onto the platform, a blaze will spawn in seconds at my exact location.  Further blazes might spawn at the location of the existing blaze.  A zombie pigman on the platform also allows blazes to spawn at the pigman's exact location.

 

Problem continues to exist in 1.14.4-forge-28.0.17.  Vanilla 1.14.3 and 1.14.4 do not exhibit this behavior.

Edited July 26, 2019 by TupeloSchneck
typo