Just shooting the breeze now, it is:
Matilda II Infantry Tank
My shield is the heaviest, slowly when I moving.
Explanation from OP:
Matilda's armor was the heaviest among the medium tanks of its era, and made it too heavy to move swiftly. (14 to 26 km per hour)
Tank hull armor comparison:
(according to Wikipedia, along with armor scheme from various reference)
Matilda II (1939 to 1942) - 78mm (3.1 in) at minimum 10 degree
(Image reference here)
Pz.Kpfw. III Ausf. J (1941/42) - 50mm (1.97 in) at 22 degree
(Image reference here)
Pz.Kpfw. IV Ausf. F1 (1941/42) - 50mm (1.97 in) at 14 degree
(Image reference here)
M4A2 Sherman (1942 to 1944) - 50mm (1.97 in) at 58 degree
(Image reference here)
T-34/76 1941 model (along with T-34-85) - 45mm (1.77 in) at 60 degree
(Image reference here)
Poor at bombing, yet good at piercing.
Explanation from OP:
It refers to Matilda II's QF 2-pounder (40mm) tank gun (the key line to distinguish the solution from the Matilda I), which is effective in armor penetration at the early time of war, yet it was not able to blast enemy position, due to the lack of high explosive (HE) shells.
Even though Matilda tank equipped with HE shells later, its firepower was not heavy enough, compared with Sherman's 75mm tank gun.
For some I am a support, for others I am a trouble.
Explanation from OP:
Apparently, Matilda tanks was for infantry support to the British, and a nasty trouble to the German - especially in the early phase of World War 2.
Even the shells poured, the defense still stable.
During the battle of France, Matildas proved to be resistant to German 37mm anti-tank guns (but not their 88s). This is also their first meeting with The Fennec (though he wasn't called that back then)
In honor of my protection, I even got coronated.
Explanation from OP:
According to Wikipedia,
"... for a time in 1940–1941, the Matilda earned the nickname "Queen of the Desert"."
The reference was not point out how the nickname came from, but I think it refers to Operation Compass, a battle which the British troops defeated the Italian forces in Egypt and Libya.
Until a pole turned downward, then my shield got penetrated.
That line is about the 88s. Having been repelled by these slow by seemingly invulnerable machines, The Fennec ordered a group of support Artillery cannons (105mm howitzers, and the legendary 8.8cm FLAKs) to try and shoot at them instead. That worked.
Hint 1:
For futher information of "troubleshooting", the "fox" found a way to it.
"The Fennec" "shot" this "touble" in Africa. A lot.
Explanation from OP (additional):
Both "The Fox" and "The Fennec" refers to Erwin Rommel who is well known as the Desert Fox.
Hint 2:
God Save the Queen, yet this "queen" can't be saved all the time in World War 2.
This "queen" can't be saved all the time? Not from The Fennec, apparently.
Explanation from OP (additional):
The Matilda II tanks had met their Nemesis twice during the war:
First, in the Battle of Arras, then being foiled again in Operation Battleaxe.
As the Second Battle of El Alamein begun, the Matilda tanks had became the scavanger in the Devil's gardens.