Hello,

Time compression stops compressing time after ~2sec of it being turned on.
The ACCEL text is ON and showing on screen, but time slows down to the normal time passing after ~2sec, so I have to constantly turn it OFF and back ON again to get any time compression going.

I remember this issue from way back in '90s when I played the game on my 486.

I don't think this is a bug. I experienced this as well. The game goes back to normal time when something important happens: a SAM launching a missile, you being detected by an enemy jet, etc.

No, then the ACCEL label dissapears as it's auto turned off.
As I said my ACCEL stays on, even when nothing happens, right after taking off, but time compression stops and time flows normally 2sec after I turn it ON.

It's not a bug but more a strange design decission, time accelleration stops every time you are being "pinged" by radar.

Your acceleration stops when the game action occurs. This is when you get hit by radar or a missile. Just reelect it until the next time you are pinged. This was in the game instructions. Also remember that you can fly different angles to avoid radar. That also is in the manual.

not what I mean

1. you start time acceleration
2. time acceleration is shown as turned on hud ACCEL
3. time starts flowing faster
4. after ~1sec time acceleration slows down to about x1.5
5. after ~1sec time acceleration slows down to x1
6. hud still displays time acceleration as turned on - ACCEL

time flows x1 until you turn acceleration off and on again, for ~2sec until it slows down again