SOQL OFFSET with long text area fields in the query cause unexpected record cut-off

apex.cls

/* setup */
Account[] accs = new Account[] {};
for (Integer i = 1; i <= 3000; i++) {
  accs.add(new Account(Name = 'Test Account #' + i));
}
insert accs;

/* start test */
Account[] recs;
recs = [
    SELECT Id, Name, LongTextarea01__c
    FROM Account
    WHERE Name LIKE 'Test Account%'
];
// expected to show `3000`, and actually does.
System.debug('Rows = ' + recs.size());

recs = [
    SELECT Id, Name, LongTextarea01__c
    FROM Account
    WHERE Name LIKE 'Test Account%'
    OFFSET 1
];
// expected to show `2999`, and actually shows `250`
System.debug('Rows (with offset 1) = ' + recs.size());

recs = [
    SELECT Id, Name, LongTextarea01__c, LongTextarea02__c
    FROM Account
    WHERE Name LIKE 'Test Account%'
    OFFSET 1
];
// expected to show `2999`, and actually shows `125`
System.debug('Rows (with offset 1, two LTA fields) = ' + recs.size());

recs = [
    SELECT Id, Name, LongTextarea01__c, LongTextarea02__c, LongTextarea03__c
    FROM Account
    WHERE Name LIKE 'Test Account%'
    OFFSET 1
];
// expected to show `2999`, and actually shows `62`
System.debug('Rows (with offset 1, three LTA fields) = ' + recs.size());

recs = [
    SELECT Id, Name
    FROM Account
    WHERE Name LIKE 'Test Account%'
    OFFSET 1
];
// expected to show `2999`, and actually does.
System.debug('Rows (with offset 1, no LTA fields) = ' + recs.size());

Integer cnt;
cnt = 0;
for (Account rec: [
    SELECT Id, Name, LongTextarea01__c
    FROM Account
    WHERE Name LIKE 'Test Account%'
    OFFSET 1
]) {
    cnt++;
}
// expected to show `2999`, and actually shows `200`.
System.debug('Rows (with offset 1, using for-loop) = ' + cnt);

cnt = 0;
for (Account rec: [
    SELECT Id, Name, LongTextarea01__c, LongTextarea02__c
    FROM Account
    WHERE Name LIKE 'Test Account%'
    OFFSET 1
]) {
    cnt++;
}
// expected to show `2999`, and actually shows `200`.
System.debug('Rows (with offset 1, two LTAs, using for-loop) = ' + cnt);

cnt = 0;
for (Account rec: [
    SELECT Id, Name, LongTextarea01__c, LongTextarea02__c, LongTextarea03__c
    FROM Account
    WHERE Name LIKE 'Test Account%'
    OFFSET 1
]) {
    cnt++;
}
// expected to show `2999`, and actually shows `200`.
System.debug('Rows (with offset 1, three LTAs, using for-loop) = ' + cnt);

/* teardown */
delete accs;