I reported the same problem on the beta testing site for Realband on 19th April 2025. Had a discussion with Simon, but not sorted it yet. this is a copy of the OP.

There appears to be an excessive delay when recording MIDI to RB 2025.

I tested this first of all on a desktop PC with a quad-core AMD Rysen and 16g RAM, running an up-to-date copy of Windows 11 Pro. For the test, the settings in MIDI Devices were all set to default.

The test consisted of a track with a quantised stick click playing four to the bar at 120 bmp. The click was generated firstly by Coyote and then by Speedrum and the tracks were monitored using a Behringer UMC404HD interface and Sennheiser headphones. Tracks were then recorded using an M-Audio keyboard and an Akai MPD218, both connected directly by USB to the PC and with both sound sources producing a snare drum sound. The difference between all the tracks was compared using the MIDI slide feature and revealed a delay on all the recorded tracks of between 24 to 26 clocks (allowing for playing error, say 25 ave.)
I then performed an identical test on my AMD twin-core desktop PC with 8g RAM, Windows 8.1 and RB 2021. There was a difference between the click track and the recorded tracks of +/- 2 clocks - no discernible error on ave. Another test was performed using an old copy of PT2013 on this same machine with the same results. To complete the tests, I put a copy of PT 2013 onto the first test PC and repeated the test - still no measurable error.

The error doesn't happen when recording audio - a damped guitar note recorded to the click track through the Behringer UMC404HD shows no appreciable delay on RB 2025. Of course, there may be something I'm missing here, but maybe someone can either duplicate this error, or point out where I've gone wrong.

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