Bug?static noise at the beginning of audio recordings

[bigjoe]

Hi everyone,
A friend of mine has a major problem with Reaper and a Behringer 1820.
Every time he records something with the monitoring activated, he obtain a strong static noise at the beginning of the file, after a while Reaper records everithing fine.
The static isn’t just a monitoring issue, since the noise is recorded in the file itself.
Seems like the cursor start slow...then accelerate and after a while goes smoothly and the static go away.
We tried chaging buffer from 256 to 1024, we tried to check for sample-rate mismatches between project and interface, we tried to change every thing in the preferences but nothing changes.
The problem came out after a audio driver update, so he tried to downgrade, but the problem is still here.
We tried to run a test with ProTools first and the interface worked as expected, no static noise, everithing runs smoothly.

The question is: what can be the reason for this static in reaper? There’s a problem with some settings or is a bug?
We tested this in reaper 6.14, 6.15, 6.17 and 6.18

Thanks in advance ��