Delay recording issues!

Hello there!
I have a issue with Cubase Pro 10.5. This also applies to Cubase Pro 10. In cubase elements 9 is working.
When i record, i have a slight delay from the moment that i record the vocal, to when i play it. The singer is on sync, but after playback, the vocals are delayed, whenever i insert a plugin on that track. I must specify that on Pro Tools HD 12, i do not have this issue, so it is basically a software issue, or a setting.
Now, let me tell you, i have set the lowest latency, i use an Antelope Orion HD soundcard. So this is not the problem.
Let me be more specific.
I open a new project, load the instrumental, adding a new mono audio track.
Now, i monitor the sound thru the soundcard, not from Cubase, so there are no plugins inserted on the track to affect this, so i record without any plugins on any channel.
After the recording, if i add on the channel any VST Plugins, the vocals are delayed from the beat. Even the metronome goes out of sync.
Now, i tried to record with delay compensation on or off, no change, i tried to adjust the record shift in the settings with the calculated specific input delay, same issue.
I tried to record also with the plugins already inserted on the channel and to calculate the delay to shift it, i still have the same issue.
Now, i need to specify clearly that in Pro Tools, this is working with or without having any vst’s inserted on the channel. It seems to be some kind of configuration that i miss or something … maybe you can help. I can tell you from the start that i have a good computer, good ssd’s etc. so the problems is not from my hardware, i just wanted to eliminate that. Let me know if somebody else is having the same issue or what can i do?