I am currently facing an issue that I would like to seek your assistance with. Here's a brief overview of my setup:

I receive bandwidth from my ISP on the core router. From this core router, I have connected a BDCOM Switch (Model: S2928EF-2AC). The distributed routers are then connected to this BDCOM switch.

I am attempting to bond two ports on my MikroTik router with two ports on the BDCOM switch for load balancing. However, this configuration does not seem to be working as expected.

Could you please provide some guidance or suggest a solution to resolve this issue?

Thank you in advance for your support. I look forward to your response.

Look into 802.3ad bonding (a.k.a LACP). This has to be configured (and, above all, supported) on both sides. Bonds work best if all bond members use same speed.

And beware that 802.3ad doesn't provide any mode which evenly distributes traffic between bond members "no matter what", it's always up to transmitting device to (more or less) inteligently select bond member for next frame to be transmitted. In most cases frames belonging to same connection (whatever that might be) use the same bond member. Given enough independent connections traffic will more or less evenly distribute over bond members, but none of connections will be able to reach speeds higher than speed of single bond member.

Actual bond configuration on Mikrotik depends on model of router device, some include switch chip which can do bonding in hardware, others have to do it in software (which loads main CPU and could limit router's overall performance).

Try using mode: 802.3ad
Most switch support it.