I recently submitted an "Enter the Nether" RSG run. I can not think of any reason why it was declined. 
Here is the run: https://www.youtube.com/watch?v=8H6uNcb1484

it shows the reason why it got rejected below, its probably because you didnt put a seed in the description

Why was this run declined?

Khalooody

Yoopicul

Vedertesu

12stoutstreet

Mattgwat

Smemzy

Deux

Minecraft: Java Edition Category Extensions

Mo_An

Leizhen_Tian

MicrowaveCaprison

dekuuu

bootyman74

Diamond

Cake

Golden Apple

Emerald

Structures

No Structures

Wither

Elder Guardian

All Bosses

Set Seed Glitchless

Random Seed Glitchless

1.10

1.11

1.12

1.13

1.14 Easy

Normal

Hard

Hardcore

1.8.9

1.12.2

1.14.2

1.7.2

1.14.4

1.14.3

1.13.2

1.5.2

1.8.8 No F3

1.7.9

1.2.1

1.2.2

1.2.3

1.2.4

1.2.5

1.7.10

1.3.1

1.3.2

1.4.2

1.4.4

1.4.5

1.4.6

1.4.7

1.5.1

1.6.1

1.6.2

1.6.4

1.7.4

1.7.5

1.7.6

1.7.7

1.7.8

1.8.1

1.8.2

1.8.3

1.8.4

1.8.5

1.8.6

1.8.7

1.9.1

1.9.2

1.9.3

1.9.4

1.10.1

1.10.2 Item

Structures (Obtain Item)

Boss

SS/RS/SSG/RSG (Kill Bosses)

SSG/RSG (Enter Nether)

SSG/RSG (All Swords)

SSG/RSG (All Woods)

SSG/RSG (All Wool)

SSG/RSG (Full Iron 15 Levels)

SS/RS/SSG/RSG (HDWGH)

Version

Difficulty

Sub Version

Structures (Enter Nether)

Structures (All Swords)

Structures (Full Iron 15 Levels)

SSG/RSG (All Minerals)

Structures (All Minerals)

Version (All Bosses)

Mods

SSG/RSG (Hero of the Village)

SSG/RSG (All Workstations)

SSG/RSG (Full Inventory)

Structures (Full Inventory)

Version (All Swords)

Version (All Minerals)

Version (All Wood Logs)

SS/SSG (Enter End)

SSG/RSG (Arbalistic)

Item (Glitched)

SS/RS (Enter Nether (Glitched))

SS/RS (All Wool (Glitched))

SS/RS (Full Iron + 15 Levels (Glitched))

Structures (Full Iron Armor + 15 Levels (Glitched))

SSG/RSG (Obtain Item)

SS/RS (All Swords (Glitched))

Structures (Arbalistic)

SSG/RSG (All Versions)

Version Range

Difficulty (All Versions)

SSG/RSG (Sonic, Tails, and Knuckles)

SSG/RSG (20w14∞)

SS/SSG/RS/RSG (Mine a Chunk)

Dimension (Mine a Chunk)

SS/SSG/RS/RSG (Stack of Lime Wool)

SS/SSG/RS/RSG (All Portals)

Version (Filtered Seed Glitchless)

Player Count (Mine a Chunk)

Subcategory (15w14a)

SS/SSG/RS/RSG (15w14a)

Version (Half%)

SS/SSG/RS/RSG (Half%)

Player Count (Filtered Seed Glitchless)

Version (All Wool)

/seed (SRG)

SSG/RSG (Pride%)

RSG/SSG/RS/SS High%

Version (HDWGH)

Version (All Portals)

SSG/RSG (Cover Me in Debris)

Structures (Cover Me in Debris)

Version (Enter Nether)

Version (Mine a Chunk)

### Updated requirements for Category Extensions

Submissions for Category Extensions must now follow the same standards of showing F3 asked of main board runs - showing the title screen will no longer be considered verifiable going forwards.

Updated requirements for Category Extensions

1.19 Categories + Cover Me In Debris

Category Extensions Update

Minecraft

Category Extensions Extensions

Please request new categories in #category-submissions on the discord

Rules Update (Providing Seed)

Poll: Allow Dungeons And Nether Fortresses (1.0-1.7.10) in categories with No Generated Structures.