Signs given to player that contain (an) NBT tag(s) lose those tags when sign placed in survival mode.

Reproduce 1:
1. issue command via console or command block:

give @p sign 1 0 {BlockEntityTag:{Text1:"{\"text\":\"Line 1\"}",Text2:"{\"text\":\"Line Two\"}",Text3:"{\"text\":\"3rd Line\"}",Text4:"{\"text\":\"last line\"}"},display:{Name:"Custom Sign"}}

2. survival-mode player receives item
3. survival-mode player places item in-game and sign UI prompts for text, i.e. NBT tags are lost

Reproduce 2:
1. issue command via console or command block:

give @p sign 1 0 {BlockEntityTag:{Text1:"{\"text\":\"-OFFSET-\",\"color\":\"blue\",\"bold\":true,\"clickEvent\":{\"action\":\"run_command\",\"value\":\"tp @p ~ ~5 ~\"}}",Text2:"{\"text\":\"\"}",Text3:"{\"text\":\"bed\",\"color\":\"black\"}",Text4:"{\"text\":\"\"}"},CustomName:"Sign",display:{Name:"MCI TP Sign",Lore:["MCI TP Sign","Once placed, establishes an offset teleport to ~ ~5 ~","If the sign is broken, it drops a regular sign."]}}

2. survival-mode player receives item; hovering over the item in inventory shows display name and lore
3. survival-mode player places item in-game and sign UI prompts for text input, i.e. all NBT tags are lost

Repeating either example above while player is in creative mode produces the expected results, i.e. the sign retains its NBT tags.