AP Pro Duo bridging mode slow

I am using ap pro duo s in bridging mode. Tests, using a minimal configuration to isolate the pepwave devices, show that we achieve less than 10 percent of the specified performance for throughput speed.

Has anybody else encountered such problems? I have methodically tweaked the configuration for some time now but have not achieved the desired performance. I’d be really grateful to receive helpful ideas from others who have been through this.