You may want to sanitize a bit more than you did (key).
Also that is not in standard order, I had to use "CTRL-F" to find the bridge. You also didn't paste into a </> block.
There is no need for a second bridge, there are very few cases where multiple bridges are required, and I have never used more than one. But the RB4011 does have 2 switch chips, so I believe it is possible to have 2 HW offloaded bridges on that device, but only if all members of each vlan are on the same switch chip. As you have it configured, with TrunkB-Eth5 on ports 5-8, it is not optimal.
See https://cdn.mikrotik.com/web-assets/product_files/RB4011iGSplusRM_180903.png
But that isn't the cause of the issue you are seeing.
Be aware that when you ping an interface on the router itself, it isn't using the forward chain.
Here's your original trouble report:
That says you were trying to block traffic between vlans.
Before anyone tries to dissect your (hard to read) config, can you show us what does not work?
Have you tried between devices in the different vlans?
a network diagram - even a photo of a hand drawn sketch is much easier to quickly understand than a bunch of words.
How to export, sanitize and post config on forum - gigabyte091
Please follow the standard litany when giving a problem report. From Frequently Given Answers written by JdeBP
How to Report Bugs Effectively from PuTTY author Simon Tatham's Home Page