SQL Server 2017

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CREATE TABLE dbo.employee (Ecode varchar(10));

INSERT INTO dbo.employee
VALUES('BUL-SJU-01'),
	  ('BUL-PLA-05'),
	  ('BUL-PLA-03'),
	  ('BUL-MAL-03'),
	  ('BUL-CAL-01'),
	  ('BUL-BOC-01');
6 rows affected

CREATE TABLE dbo.schedule ([user_id] varchar(10));
CREATE TABLE dbo.[order] (Ecode varchar(10));
CREATE TABLE dbo.store (Ecode varchar(10));
--Make Schedule sample data
WITH N AS(
	SELECT N
	FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
	SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS I
	FROM N N1, N N2, N N3)
INSERT INTO dbo.schedule ([user_id])
SELECT V.ecode
FROM (VALUES('BUL-SJU-01',135),
		    ('BUL-PLA-05',1  ),
		    ('BUL-PLA-03',121),
		    ('BUL-MAL-03',128),
		    ('BUL-CAL-01',48 ),
		    ('BUL-BOC-01',111))V(ecode,Num)
	 JOIN Tally T ON Num >= T.I;
	 
WITH N AS(
	SELECT N
	FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
	SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS I
	FROM N N1, N N2, N N3)
INSERT INTO dbo.[order] (Ecode)
SELECT V.ecode
FROM (VALUES('BUL-SJU-01',7 ),
			('BUL-PLA-05',0 ),
			('BUL-PLA-03',0 ),
			('BUL-MAL-03',3 ),
			('BUL-CAL-01',10),
			('BUL-BOC-01',11))V(ecode,Num)
	JOIN Tally T ON Num >= T.I;
	
WITH N AS(
	SELECT N
	FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
	SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS I
	FROM N N1, N N2, N N3)
INSERT INTO dbo.store (Ecode)
SELECT V.ecode
FROM (VALUES('BUL-SJU-01',135),
		    ('BUL-PLA-05', 0 ),
		    ('BUL-PLA-03',120),
		    ('BUL-MAL-03',128),
		    ('BUL-CAL-01',46 ),
		    ('BUL-BOC-01',111))V(ecode,Num)
	JOIN Tally T ON Num >= T.I;
1115 rows affected

--OP's incorrect query:
SELECT 
emp.[ecode],
COUNT(sch.[user_id]) as schedulecount,
COUNT(ord.[ecode]) as noordercount,
COUNT(sto.[ecode]) as salescount
FROM [dbo].[employee] as emp
INNER JOIN [dbo].[schedule] as sch 
ON  sch.[user_id] = emp.[ecode]
INNER JOIN [dbo].[order] as ord
ON  ord.[ecode] = emp.[ecode]
INNER JOIN [dbo].[store] as sto
ON  sto.[ecode] = emp.[ecode]
 GROUP BY 
 emp.[ecode]
 ORDER BY
 emp.[ecode] DESC;


ecode
schedulecount
noordercount
salescount


BUL-SJU-01
127575
127575
127575

BUL-MAL-03
49152
49152
49152

BUL-CAL-01
22080
22080
22080

BUL-BOC-01
135531
135531
135531


--My query, giving results correct per question:
SELECT emp.ecode,
       Sc.schedulecount,
       O.noordercount,
       St.salescount
FROM dbo.employee emp
     CROSS APPLY (SELECT COUNT(*) AS schedulecount
                  FROM dbo.schedule sch
                  WHERE sch.user_id = emp.ecode) Sc
     CROSS APPLY (SELECT COUNT(*) AS noordercount
                  FROM dbo.[order] ord --Generally it's a good idea to avoid Reserved Keywords for Object names
                  WHERE ord.ecode = emp.ecode) O
     CROSS APPLY (SELECT COUNT(*) AS salescount
                  FROM dbo.store sto
                  WHERE sto.ecode = emp.ecode) St
ORDER BY emp.ecode DESC;


ecode
schedulecount
noordercount
salescount


BUL-SJU-01
135
7
135

BUL-PLA-05
1
0
0

BUL-PLA-03
121
0
120

BUL-MAL-03
128
3
128

BUL-CAL-01
48
10
46

BUL-BOC-01
111
11
111

ecode	schedulecount	noordercount	salescount
BUL-SJU-01	127575	127575	127575
BUL-MAL-03	49152	49152	49152
BUL-CAL-01	22080	22080	22080
BUL-BOC-01	135531	135531	135531

ecode	schedulecount	noordercount	salescount
BUL-SJU-01	135	7	135
BUL-PLA-05	1	0	0
BUL-PLA-03	121	0	120
BUL-MAL-03	128	3	128
BUL-CAL-01	48	10	46
BUL-BOC-01	111	11	111