A strength value of 0 shouldn't be possible. I've added more console logs, try loading again and tell me what you see.
Here are the results of my loading.
Load from the main menu:
onLoad running, save version = 36 index.html line 31442 > eval:1004:10
Forge puzzle should have been reset, new strength value = 1 index.html line 31442 > eval:1483:12
Reload 1:
onLoad running, save version = 36 index.html line 31442 > eval:1004:10
special index.html line 31442 > eval:1:9
_rand = 0 index.html line 31442 > eval:1:9
_rand adjustment triggered index.html line 31442 > eval:1:9
final _rand = -1 index.html line 31442 > eval:1:9
Forge puzzle should have been reset, new strength value = -1 index.html line 31442 > eval:1483:12
Reload 2:
onLoad running, save version = 36 index.html line 31442 > eval:1004:10
no special index.html line 31442 > eval:1:9
Forge puzzle should have been reset, new strength value = 0 index.html line 31442 > eval:1483:12
Reload 3:
onLoad running, save version = 36 index.html line 31442 > eval:1004:10
special index.html line 31442 > eval:1:9
_rand = 0 index.html line 31442 > eval:1:9
_rand adjustment triggered index.html line 31442 > eval:1:9
final _rand = -1 index.html line 31442 > eval:1:9
Forge puzzle should have been reset, new strength value = -1 index.html line 31442 > eval:1483:12
Reload 4:
onLoad running, save version = 36 index.html line 31442 > eval:1004:10
special index.html line 31442 > eval:1:9
_rand = 1 index.html line 31442 > eval:1:9
final _rand = 1 index.html line 31442 > eval:1:9
Forge puzzle should have been reset, new strength value = 1 index.html line 31442 > eval:1483:12