I created a template to replicate my environment. I'm using a CRS328, connected to a SG200, whit latest update on both devices, Mirkotik is using last long-term. I set Up trunk/tagged interface with 1UP,10T,20T,99T on cisco sg200 (Is directly connected to CRS on sfp-plus 4). I enabled one access port with 99UP on Cisco device, I'm connected to the las mentioned port, but still I can't reach Mikrotik IP address. I'm in the same range at /21 with static IP on my device.

Please post the config
/export hide-sensitive file=anynameyouwish

Please post the config
/export hide-sensitive file=anynameyouwish

Sure I will give you the configuration. Now I'ts responding well on interface 1 on the Mikrotik itself, with access/untagged port with vlan=99. I'm gonna rebuild the Cisco device with trunks and I will try again. It seems like a problem with import of my template, I did not find nothing at first place...

(1) You need to define vlans 10 and 20 and their interface is the bridge, thus far only vlan99 is configured.

(2) You dont have vlan20 noted in the bridge vlan configuration.

(3) SFP+3 and SFP+4 are not configured on the bridge port settings??

(4) SFP+1 and FP+2 are not configured in bridge vlans??

(3) Bit confusing but is the switch creating all the vlans, as I DONT SEE A TRUNK PORT WHERE THESE ARE COMING IN FROM???
If this unit is creating the vlans from scratch, then where is DHCP done???

A network diagram would be extremely useful!!

vLAN 10 is defined in line 71 in ILikeU.rsc: The only one that is not already defined is vLAN 20 (But this is not the problem).

Line 71 and 75 u can see sfp3 and sfp4 configured as tagged/trunk ports on bridge1:
That is the network Diagram: I'ts not the full diagram, because we can discuss for a year about it, but I only need to solve this particular problem. DHCP server are not in VLAN, the whole network is on layer 2 device with no VLAN capability. I defined 2 ports as access ports which are connected to L2 switches, then I tag the packets from this point to above. Right now access ports are working fine. The problem is the trunk ports, sfp-plus3 and sfp-plus4 are not trunking into cisco sg200 device. The problem which I mentioned days later was caused while importing the template.

Since you think defining a vlan is done in Bridge vlan settings and that only providing a partial network diagram is good enough, suggest someone else help.
I can suggest reading this excellent link
viewtopic.php?f=23&t=143620