How do you switch ProfPZU banks in Scorpa?

I was fiddling with the subject. I don't understand anything.

ORG #6200
DI
LD BC,#1FFD
LD A,#12
OUT (C),A
LD B,#7F
LD A,#10
OUT (C),A
LD A,5
CALL PAGE

KEY XOR A
IN A,(#FE)
CPL
AND #1F
JR Z,KEY

LD A,0
CALL PAGE
LD BC,#1FFD
XOR A
OUT (C),A
LD B,#7F
LD A,#10
OUT (C),A
RET

PAGE
; JP #E4AA
LD C,A
LD HL,#0110
RRCA
RRCA
AND 03
ADD A,L
LD L,A
LD L,(HL)
LD L,(HL)
LD A,C
RET

If you use the procedure from the 8th jar at the address #E4AA - then everything is fine.
If you use a similar procedure, but not located in the 8th bank, then nothing
switches.

What is this? Z80Stealth emulator glitch?

* Original written in ZX.SPECTRUM
* also sent to CODE.ZX
* also sent to REAL.SPECCY

WBR, Jason.

/*e-mail: jason2000(scary dog)yandex.ru ICQ: 62235830*/

/np:/ *silence*